The response functions and pulse height spectrum(PHS) of a 2''×2'' BC501A detector were obtained through a general-purpose Monte Carlo simulation toolkit,Geant4.A relatively simple but effective m...The response functions and pulse height spectrum(PHS) of a 2''×2'' BC501A detector were obtained through a general-purpose Monte Carlo simulation toolkit,Geant4.A relatively simple but effective method was adopted to unfold the PHS.Recommendations regarding the response matrix were proposed to optimize the unfolding results.The results indicate that the accuracy of the unfolding can be greatly improved using many incident neutrons with a wide energy range,a proper energy interval,and an appropriate channel width of the response matrix.The above-mentioned method was verified by unfolding three different types of simulated spectrum,the results of which are in good accord with the simulated distribution.展开更多
We have previously shown that the diphtheria toxin variant CRM 197 （cross-reacting material 197） can be overexpressed in Escherichia coli at high levels, yielding insoluble aggregates, which were solubilized using u...We have previously shown that the diphtheria toxin variant CRM 197 （cross-reacting material 197） can be overexpressed in Escherichia coli at high levels, yielding insoluble aggregates, which were solubilized using urea. This study reports a comparison of three matrices suitable for the purification and refolding of recombinant CRM197 by metal-chelating affinity chromatography, Moreover, we show that refolded CRM197 features enzymatic activity.展开更多
In this article, we propose a parameter vertex method to determine the upper and lower bounds of the dynamic response of structures with interval parameters, which can be regarded as an extension of the matrix vertex ...In this article, we propose a parameter vertex method to determine the upper and lower bounds of the dynamic response of structures with interval parameters, which can be regarded as an extension of the matrix vertex method proposed by Qiu and Wang. The matrix vertex method requires considerable computation time and encounters the dependency problem in practice,thereby limiting its application in engineering. The proposed parameter vertex method can avoid the dependency problem, and the number of possible vertex combinations in the proposed method is significantly less than that in the matrix vertex method.The parameter vertex method requires that each matrix element in the dynamic differential equation is monotonic with respect to the uncertain parameter, and that the dynamic response reaches its extreme value when the uncertain parameter is at its endpoint.To further reduce the runtime, both vertical and transversal parallel algorithms are introduced and integrated into the parameter vertex method to improve its computational efficiency. Two numerical examples are presented to demonstrate the proposed method combined with both parallel algorithms. The performances of the two parallel algorithms are thoroughly studied. The parameter vertex method combined with parallel algorithm can be used for large-scale computing.展开更多
基金supported by the Funding Agency ITER(No.2014GB11204)
文摘The response functions and pulse height spectrum(PHS) of a 2''×2'' BC501A detector were obtained through a general-purpose Monte Carlo simulation toolkit,Geant4.A relatively simple but effective method was adopted to unfold the PHS.Recommendations regarding the response matrix were proposed to optimize the unfolding results.The results indicate that the accuracy of the unfolding can be greatly improved using many incident neutrons with a wide energy range,a proper energy interval,and an appropriate channel width of the response matrix.The above-mentioned method was verified by unfolding three different types of simulated spectrum,the results of which are in good accord with the simulated distribution.
文摘We have previously shown that the diphtheria toxin variant CRM 197 （cross-reacting material 197） can be overexpressed in Escherichia coli at high levels, yielding insoluble aggregates, which were solubilized using urea. This study reports a comparison of three matrices suitable for the purification and refolding of recombinant CRM197 by metal-chelating affinity chromatography, Moreover, we show that refolded CRM197 features enzymatic activity.
基金supported by the Defense Industrial Technology Development Program(Grant Nos.2016YFB0200700,JCKY2016601B001,and JCKY2016204B101)the Program of Introducing Talents of Discipline to Universities of China(111 Project)(Grant No.B07009)National Nature Science Foundation of China(Grant Nos.11372025,11432002,and11572024)
文摘In this article, we propose a parameter vertex method to determine the upper and lower bounds of the dynamic response of structures with interval parameters, which can be regarded as an extension of the matrix vertex method proposed by Qiu and Wang. The matrix vertex method requires considerable computation time and encounters the dependency problem in practice,thereby limiting its application in engineering. The proposed parameter vertex method can avoid the dependency problem, and the number of possible vertex combinations in the proposed method is significantly less than that in the matrix vertex method.The parameter vertex method requires that each matrix element in the dynamic differential equation is monotonic with respect to the uncertain parameter, and that the dynamic response reaches its extreme value when the uncertain parameter is at its endpoint.To further reduce the runtime, both vertical and transversal parallel algorithms are introduced and integrated into the parameter vertex method to improve its computational efficiency. Two numerical examples are presented to demonstrate the proposed method combined with both parallel algorithms. The performances of the two parallel algorithms are thoroughly studied. The parameter vertex method combined with parallel algorithm can be used for large-scale computing.
