The solubilities of some solid n-alkanes in supercritical ethane were correlated and predicted in this paper using the Carnahan-Starling-van der Waals model with a density-dependent parameter of a12.At a given tempera...The solubilities of some solid n-alkanes in supercritical ethane were correlated and predicted in this paper using the Carnahan-Starling-van der Waals model with a density-dependent parameter of a12.At a given temperature,the linear fit of the parameter of a12and the density of the supercritical solvent was used for solubility correlation,resulting in an average absolute average relative deviation(AARD)of 8.68%,which was between the values of the semiempirical models and the other compressed gas models used in this article.In the linear fit of the parameter of a12and the density of the solvent,the regressed slope m and intercept n of the linear fit can be correlated with the carbon atom number of solid n-alkanes and then the solubilities of solid n-alkanes in supercritical ethane can be predicted with the intercept n and slope m.The average AARD in solubility prediction was 26.99%.展开更多
In this paper, a class of n coupled van der Pol oscillator model with delays is considered. By employing an analysis approach, some sufficient conditions to guarantee the existence of stability and oscillations for th...In this paper, a class of n coupled van der Pol oscillator model with delays is considered. By employing an analysis approach, some sufficient conditions to guarantee the existence of stability and oscillations for themodel are obtained. Examples are provided to demonstrate the results.展开更多
This paper proposes an impulsive control scheme for chaotic systems consisting of Van der Pol oscillators coupled to linear oscillators （VDPL） based on their Takagi-Sugeno （T-S） fuzzy models. A T-S fuzzy model is ...This paper proposes an impulsive control scheme for chaotic systems consisting of Van der Pol oscillators coupled to linear oscillators （VDPL） based on their Takagi-Sugeno （T-S） fuzzy models. A T-S fuzzy model is utilized to represent the chaotic VDPL system. By using comparison method, a general asymptotical stability criterion by means of linear matrix inequality （LMI） is derived for the T-S fuzzy model of VDPL system with impulsive effects. The simulation results demonstrate the effectiveness of the proposed scheme.展开更多
目的对粉尘螨的过敏原蛋白之一的der f 28的结构与性质进行生物信息方面的分析,为粉尘螨所导致的变态反应性疾病的诊断和治疗提供线索。方法通过对der f 28进行BLAST得到的相似序列进行构建进化树,同时对der f28的二级结构、亲水性区域...目的对粉尘螨的过敏原蛋白之一的der f 28的结构与性质进行生物信息方面的分析,为粉尘螨所导致的变态反应性疾病的诊断和治疗提供线索。方法通过对der f 28进行BLAST得到的相似序列进行构建进化树,同时对der f28的二级结构、亲水性区域、可塑性区域、抗原性区域进行分析。结果粉尘螨与其他微生物物种中的热休克蛋白70（HSP70）在进化上相似性不高。der f 28的主要抗原位点为24~39、93~103、150~163、202~205、244~281、414~434、450~484、551~605。Motif的预测表明der f 28具有热休克蛋白70家族的特征。其预测的三维结构基本能反应der f 28真实的空间构象。结论掌握der f 28结构和功能的的关系,对粉尘螨所引起的变态反应性疾病的诊断和治疗有临床意义。展开更多
基于流体体积分数的混合型多流体数值模型,将Piecewise Parabolic Method(PPM)方法应用于可压缩多流体流动的数值模拟,采用双波近似求解多流体van der Waals状态方程的Riemann问题.模拟高密度比且含有激波的可压缩多流体流动,典型的纯...基于流体体积分数的混合型多流体数值模型,将Piecewise Parabolic Method(PPM)方法应用于可压缩多流体流动的数值模拟,采用双波近似求解多流体van der Waals状态方程的Riemann问题.模拟高密度比且含有激波的可压缩多流体流动,典型的纯界面平移问题模拟结果表明,在接触间断的界面附近,压力和速度没有任何的振荡且界面数值耗散都被控制在2-3个网格之内;一维和二维算例表明,该数值方法可以有效地处理接触间断、激波和多维滑移线等物理问题,并能够比其它多流体数值方法更精细地模拟多流体交界面.展开更多
A class of recharge–discharge oscillator model for the El Ni？o/Southern Oscillation （ENSO） is considered. A stable limit cycle is obtained by transforming the ENSO model into the van der Pol-Duffing equation. We p...A class of recharge–discharge oscillator model for the El Ni？o/Southern Oscillation （ENSO） is considered. A stable limit cycle is obtained by transforming the ENSO model into the van der Pol-Duffing equation. We proved that there exists periodic oscillations in the ENSO recharge–discharge oscillator model.展开更多
In 1981 Taiwan entered a period of intense construction, meaning that today many buildings are more than 30 years old. Lack of maintenance has led to frequent safety incidents involving external walls. This study focu...In 1981 Taiwan entered a period of intense construction, meaning that today many buildings are more than 30 years old. Lack of maintenance has led to frequent safety incidents involving external walls. This study focuses on a deterioration diagnostic model for external wall tiles of aged buildings, using both stage 1 and stage 2 diagnostic methods. The visual test results are categorized based on impact on public safety, and renovation strategies are proposed. Stage 1 diagnosis mainly adopted the DER visual inspection deterioration assessment method. For enhance the accuracy, this research adopted the Infrared Thermal Imaging detection method to double confirm the visual inspection results. After producing an external wall tile Condition Indicator (CI). For stage 1 diagnostic results that fall in a gray area, stage 2 diagnosis was carried out using a tap tone test, followed by fast Fourier transform and pattern recognition to analyze the tapping results. Finally, the study provides a deterioration evaluation criteria for external wall tiles replacement recommendations and a standard operating procedure for deterioration diagnosis. The study also recommends directions for future amendment of regulations, and provides a basis of reference for the government in determining urban renewal, renovation and maintenance strategies.展开更多
A simplified model is proposed for an easy understanding of the coarse-grained technique and for achieving a first approximation to the behavior of gases. A mole of a gas substance, within a cubic container, is repres...A simplified model is proposed for an easy understanding of the coarse-grained technique and for achieving a first approximation to the behavior of gases. A mole of a gas substance, within a cubic container, is represented by six particles symmetrically moving. The impacts of particles on container walls, the inter-particle collisions, as well as the volume of particles and the inter-particle attractive forces, obeying a Lennard-Jones curve, are taken into account. Thanks to the symmetry, the problem is reduced to the nonlinear dynamic analysis of a SDOF oscillator, which is numerically solved by a step-by-step time integration algorithm. Five applications of proposed model, on Carbon Dioxide, are presented: 1) Ideal gas in STP conditions. 2) Real gas in STP conditions. 3) Condensation for small molar volume. 4) Critical point. 5) Iso-kinetic energy curves and iso-therms in the critical point region. Results of the proposed model are compared with test data and results of the Van der Waals model for real gases.展开更多
This article focuses on the study of crushing rocks that can replace clinker in low-carbon cement. A laboratory ball mill was used, varying the duration of the grinding. It has been observed that the specific surface ...This article focuses on the study of crushing rocks that can replace clinker in low-carbon cement. A laboratory ball mill was used, varying the duration of the grinding. It has been observed that the specific surface of rocks changes in a nonlinear way with time, due to the agglomeration of particles. To this end, a mathematical model describing this evolution, which considers van der Waals forces, has been proposed. And finally, the model was adjusted regarding the experimental data. The results found show that the present model is more accurate than the classical models, because it considers the agglomeration phenomenon.展开更多
为了对满壳层原子双原子分子间的van der Waals势函数进行必要的补充,从稀有气体同核双原子分子He2、Ne2、Ar2、Kr2、Xe2以及同核双原子分子Zn2的TT势参数出发,应用TT势模型和势参数的组合规则计算得到了Zn-RG体系各分子基态的van der W...为了对满壳层原子双原子分子间的van der Waals势函数进行必要的补充,从稀有气体同核双原子分子He2、Ne2、Ar2、Kr2、Xe2以及同核双原子分子Zn2的TT势参数出发,应用TT势模型和势参数的组合规则计算得到了Zn-RG体系各分子基态的van der Waals势,并给出了各分子的光谱参数。计算结果与先前的理论和实验值进行了比较,Zn-He、Zn-Ne、Zn-Ar分子的结果与Bera的CCSD(T)结果符合的较好。最后,针对提高计算结果的精确性问题提出了今后研究的方向。展开更多
测定了25～65℃温度范围内乙醇和环己烷液体混合物的热压力系数,它们都很好地遵守我们先前提出的修正van der Waals模型.从模型参数B/A^2,可以得到乙醇自缔合的破坏与浓度间的定量关系.混合物的内压不仅取决于两个纯组分的内压,而且还...测定了25～65℃温度范围内乙醇和环己烷液体混合物的热压力系数,它们都很好地遵守我们先前提出的修正van der Waals模型.从模型参数B/A^2,可以得到乙醇自缔合的破坏与浓度间的定量关系.混合物的内压不仅取决于两个纯组分的内压,而且还与相互作用参数A_(12)展开更多
The modified van der Waals’model which has only one molecular size-dependent parameter is used to calculate the internal pressures of liquids.It is found that the model parameter has very good linear relation with th...The modified van der Waals’model which has only one molecular size-dependent parameter is used to calculate the internal pressures of liquids.It is found that the model parameter has very good linear relation with the molar volume of liquids at normal boiling point.A group contribution method is established for the molar volume of liquids at normal boiling point.Therefore the internal pressures of various liquids can be predicted.On the basis of the generalized Gibbs free energy model for mixing of liquids,proposed by our previous work,a new solubility parameter had been defined,which is equal to the ratio of the cohesive energy density with the square root of internal pressure.This definition is more strict and its range of application is more exten sive than classical Hildebrand solubility parameter.In present work,the values of new solubility parameter for 170 solvents at 298.15 K are obtained.展开更多
基金Supported by the National Natural Science Foundation of China（21206077）
文摘The solubilities of some solid n-alkanes in supercritical ethane were correlated and predicted in this paper using the Carnahan-Starling-van der Waals model with a density-dependent parameter of a12.At a given temperature,the linear fit of the parameter of a12and the density of the supercritical solvent was used for solubility correlation,resulting in an average absolute average relative deviation(AARD)of 8.68%,which was between the values of the semiempirical models and the other compressed gas models used in this article.In the linear fit of the parameter of a12and the density of the solvent,the regressed slope m and intercept n of the linear fit can be correlated with the carbon atom number of solid n-alkanes and then the solubilities of solid n-alkanes in supercritical ethane can be predicted with the intercept n and slope m.The average AARD in solubility prediction was 26.99%.
文摘In this paper, a class of n coupled van der Pol oscillator model with delays is considered. By employing an analysis approach, some sufficient conditions to guarantee the existence of stability and oscillations for themodel are obtained. Examples are provided to demonstrate the results.
文摘This paper proposes an impulsive control scheme for chaotic systems consisting of Van der Pol oscillators coupled to linear oscillators （VDPL） based on their Takagi-Sugeno （T-S） fuzzy models. A T-S fuzzy model is utilized to represent the chaotic VDPL system. By using comparison method, a general asymptotical stability criterion by means of linear matrix inequality （LMI） is derived for the T-S fuzzy model of VDPL system with impulsive effects. The simulation results demonstrate the effectiveness of the proposed scheme.
文摘目的对粉尘螨的过敏原蛋白之一的der f 28的结构与性质进行生物信息方面的分析,为粉尘螨所导致的变态反应性疾病的诊断和治疗提供线索。方法通过对der f 28进行BLAST得到的相似序列进行构建进化树,同时对der f28的二级结构、亲水性区域、可塑性区域、抗原性区域进行分析。结果粉尘螨与其他微生物物种中的热休克蛋白70（HSP70）在进化上相似性不高。der f 28的主要抗原位点为24~39、93~103、150~163、202~205、244~281、414~434、450~484、551~605。Motif的预测表明der f 28具有热休克蛋白70家族的特征。其预测的三维结构基本能反应der f 28真实的空间构象。结论掌握der f 28结构和功能的的关系,对粉尘螨所引起的变态反应性疾病的诊断和治疗有临床意义。
文摘基于流体体积分数的混合型多流体数值模型,将Piecewise Parabolic Method(PPM)方法应用于可压缩多流体流动的数值模拟,采用双波近似求解多流体van der Waals状态方程的Riemann问题.模拟高密度比且含有激波的可压缩多流体流动,典型的纯界面平移问题模拟结果表明,在接触间断的界面附近,压力和速度没有任何的振荡且界面数值耗散都被控制在2-3个网格之内;一维和二维算例表明,该数值方法可以有效地处理接触间断、激波和多维滑移线等物理问题,并能够比其它多流体数值方法更精细地模拟多流体交界面.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.40975028 and 41175052)
文摘A class of recharge–discharge oscillator model for the El Ni？o/Southern Oscillation （ENSO） is considered. A stable limit cycle is obtained by transforming the ENSO model into the van der Pol-Duffing equation. We proved that there exists periodic oscillations in the ENSO recharge–discharge oscillator model.
文摘In 1981 Taiwan entered a period of intense construction, meaning that today many buildings are more than 30 years old. Lack of maintenance has led to frequent safety incidents involving external walls. This study focuses on a deterioration diagnostic model for external wall tiles of aged buildings, using both stage 1 and stage 2 diagnostic methods. The visual test results are categorized based on impact on public safety, and renovation strategies are proposed. Stage 1 diagnosis mainly adopted the DER visual inspection deterioration assessment method. For enhance the accuracy, this research adopted the Infrared Thermal Imaging detection method to double confirm the visual inspection results. After producing an external wall tile Condition Indicator (CI). For stage 1 diagnostic results that fall in a gray area, stage 2 diagnosis was carried out using a tap tone test, followed by fast Fourier transform and pattern recognition to analyze the tapping results. Finally, the study provides a deterioration evaluation criteria for external wall tiles replacement recommendations and a standard operating procedure for deterioration diagnosis. The study also recommends directions for future amendment of regulations, and provides a basis of reference for the government in determining urban renewal, renovation and maintenance strategies.
文摘A simplified model is proposed for an easy understanding of the coarse-grained technique and for achieving a first approximation to the behavior of gases. A mole of a gas substance, within a cubic container, is represented by six particles symmetrically moving. The impacts of particles on container walls, the inter-particle collisions, as well as the volume of particles and the inter-particle attractive forces, obeying a Lennard-Jones curve, are taken into account. Thanks to the symmetry, the problem is reduced to the nonlinear dynamic analysis of a SDOF oscillator, which is numerically solved by a step-by-step time integration algorithm. Five applications of proposed model, on Carbon Dioxide, are presented: 1) Ideal gas in STP conditions. 2) Real gas in STP conditions. 3) Condensation for small molar volume. 4) Critical point. 5) Iso-kinetic energy curves and iso-therms in the critical point region. Results of the proposed model are compared with test data and results of the Van der Waals model for real gases.
文摘This article focuses on the study of crushing rocks that can replace clinker in low-carbon cement. A laboratory ball mill was used, varying the duration of the grinding. It has been observed that the specific surface of rocks changes in a nonlinear way with time, due to the agglomeration of particles. To this end, a mathematical model describing this evolution, which considers van der Waals forces, has been proposed. And finally, the model was adjusted regarding the experimental data. The results found show that the present model is more accurate than the classical models, because it considers the agglomeration phenomenon.
文摘为了对满壳层原子双原子分子间的van der Waals势函数进行必要的补充,从稀有气体同核双原子分子He2、Ne2、Ar2、Kr2、Xe2以及同核双原子分子Zn2的TT势参数出发,应用TT势模型和势参数的组合规则计算得到了Zn-RG体系各分子基态的van der Waals势,并给出了各分子的光谱参数。计算结果与先前的理论和实验值进行了比较,Zn-He、Zn-Ne、Zn-Ar分子的结果与Bera的CCSD(T)结果符合的较好。最后,针对提高计算结果的精确性问题提出了今后研究的方向。
文摘The modified van der Waals’model which has only one molecular size-dependent parameter is used to calculate the internal pressures of liquids.It is found that the model parameter has very good linear relation with the molar volume of liquids at normal boiling point.A group contribution method is established for the molar volume of liquids at normal boiling point.Therefore the internal pressures of various liquids can be predicted.On the basis of the generalized Gibbs free energy model for mixing of liquids,proposed by our previous work,a new solubility parameter had been defined,which is equal to the ratio of the cohesive energy density with the square root of internal pressure.This definition is more strict and its range of application is more exten sive than classical Hildebrand solubility parameter.In present work,the values of new solubility parameter for 170 solvents at 298.15 K are obtained.
