The key issue in accelerating method of characteristics(MOC)transport calculations is in obtaining a completely equivalent low-order neutron transport or diffusion equation.Herein,an equivalent low-order angular flux ...The key issue in accelerating method of characteristics(MOC)transport calculations is in obtaining a completely equivalent low-order neutron transport or diffusion equation.Herein,an equivalent low-order angular flux nonlinear finite difference equation is proposed for MOC transport calculations.This method comprises three essential features:(1)the even parity discrete ordinates method is used to build a low-order angular flux nonlinear finite difference equation,and different boundary condition treatments are proposed;(2)two new defined factors,i.e.,the even parity discontinuity factor and odd parity discontinuity factor,are strictly defined to achieve equivalence between the low-order angular flux nonlinear finite difference method and MOC transport calculation;(3)the energy group and angle are decoupled to construct a symmetric linear system that is much easier to solve.The equivalence of this low-order angular flux nonlinear finite difference equation is analyzed for two-dimensional(2D)pin,2D assembly,and 2D C5G7 benchmark problems.Numerical results demonstrate that a low-order angular flux nonlinear finite difference equation that is completely equivalent to the pin-resolved transport equation is established.展开更多
To perform nuclear reactor simulations in a more realistic manner,the coupling scheme between neutronics and thermal-hydraulics was implemented in the HNET program for both steady-state and transient conditions.For si...To perform nuclear reactor simulations in a more realistic manner,the coupling scheme between neutronics and thermal-hydraulics was implemented in the HNET program for both steady-state and transient conditions.For simplicity,efficiency,and robustness,the matrixfree Newton/Krylov(MFNK)method was applied to the steady-state coupling calculation.In addition,the optimal perturbation size was adopted to further improve the convergence behavior of the MFNK.For the transient coupling simulation,the operator splitting method with a staggered time mesh was utilized to balance the computational cost and accuracy.Finally,VERA Problem 6 with power and boron perturbation and the NEACRP transient benchmark were simulated for analysis.The numerical results show that the MFNK method can outperform Picard iteration in terms of both efficiency and robustness for a wide range of problems.Furthermore,the reasonable agreement between the simulation results and the reference results for the NEACRP transient benchmark verifies the capability of predicting the behavior of the nuclear reactor.展开更多
Objective:Network pharmacology method was adopted in this study to screen the target of Zhitong Rushen Decoction of the treatment to Functional Anorectal Pain(FAP)and explore its mechanism of treatment.Methods:Chemica...Objective:Network pharmacology method was adopted in this study to screen the target of Zhitong Rushen Decoction of the treatment to Functional Anorectal Pain(FAP)and explore its mechanism of treatment.Methods:Chemical components and selected targets related to the ten traditional Chinese medicine(TCM)herbs were searched through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP).Through GeneCards database,OMIM database,disease targets of FAP were searched.R language was used to screen the common targets between drugs and disease,and then the interaction network diagram of the targets was constructed by String.Cytoscape3.7.0 was applied to construct the active ingredients-targets interacted network.GO enrichment analysis and KEGG enrichment analysis of targets were based on R language.Results:Four main chemical components including quercetin,wogonin,fisetin and kaempferol were screened,and four key targets including ESR1、NOS2、PGR and CHRM3 were identified.In GO enrichment analysis,66 molecular function entries,1040 biological process entries,26 cell component entries were obtained.KEGG pathway enrichment analysis showed that zhitong rushen decoction played a therapeutic role in functional anorectal pain by regulating AGE-RAGE signaling pathway in diabetic complications,Bladder cancer,Estrogen signaling pathway,HIF-1 signaling pathway.Conclusion:Zhitong rushen decoction for the treatment of functional anorectal pain may be related to its multi-component effect on multiple targets and multiple signaling pathways,providing theoretical basis for further study of active ingredients and mechanism of action.展开更多
基金the National Key R&D Program of China(No.2018YFE0180900).
文摘The key issue in accelerating method of characteristics(MOC)transport calculations is in obtaining a completely equivalent low-order neutron transport or diffusion equation.Herein,an equivalent low-order angular flux nonlinear finite difference equation is proposed for MOC transport calculations.This method comprises three essential features:(1)the even parity discrete ordinates method is used to build a low-order angular flux nonlinear finite difference equation,and different boundary condition treatments are proposed;(2)two new defined factors,i.e.,the even parity discontinuity factor and odd parity discontinuity factor,are strictly defined to achieve equivalence between the low-order angular flux nonlinear finite difference method and MOC transport calculation;(3)the energy group and angle are decoupled to construct a symmetric linear system that is much easier to solve.The equivalence of this low-order angular flux nonlinear finite difference equation is analyzed for two-dimensional(2D)pin,2D assembly,and 2D C5G7 benchmark problems.Numerical results demonstrate that a low-order angular flux nonlinear finite difference equation that is completely equivalent to the pin-resolved transport equation is established.
基金supported by the China Postdoctoral Science Foundation(No.2021M703045)the National Natural Science Foundation of China(No.12075067)the National Key R&D Program of China(No.2018YFE0180900).
文摘To perform nuclear reactor simulations in a more realistic manner,the coupling scheme between neutronics and thermal-hydraulics was implemented in the HNET program for both steady-state and transient conditions.For simplicity,efficiency,and robustness,the matrixfree Newton/Krylov(MFNK)method was applied to the steady-state coupling calculation.In addition,the optimal perturbation size was adopted to further improve the convergence behavior of the MFNK.For the transient coupling simulation,the operator splitting method with a staggered time mesh was utilized to balance the computational cost and accuracy.Finally,VERA Problem 6 with power and boron perturbation and the NEACRP transient benchmark were simulated for analysis.The numerical results show that the MFNK method can outperform Picard iteration in terms of both efficiency and robustness for a wide range of problems.Furthermore,the reasonable agreement between the simulation results and the reference results for the NEACRP transient benchmark verifies the capability of predicting the behavior of the nuclear reactor.
基金The 13th Five-Year plan for Nanjing famous traditional Chinese medicine studio construction project(No.ZXP-2019-NJ)Nanjing medical science and technology development project(No.YKK18137)
文摘Objective:Network pharmacology method was adopted in this study to screen the target of Zhitong Rushen Decoction of the treatment to Functional Anorectal Pain(FAP)and explore its mechanism of treatment.Methods:Chemical components and selected targets related to the ten traditional Chinese medicine(TCM)herbs were searched through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP).Through GeneCards database,OMIM database,disease targets of FAP were searched.R language was used to screen the common targets between drugs and disease,and then the interaction network diagram of the targets was constructed by String.Cytoscape3.7.0 was applied to construct the active ingredients-targets interacted network.GO enrichment analysis and KEGG enrichment analysis of targets were based on R language.Results:Four main chemical components including quercetin,wogonin,fisetin and kaempferol were screened,and four key targets including ESR1、NOS2、PGR and CHRM3 were identified.In GO enrichment analysis,66 molecular function entries,1040 biological process entries,26 cell component entries were obtained.KEGG pathway enrichment analysis showed that zhitong rushen decoction played a therapeutic role in functional anorectal pain by regulating AGE-RAGE signaling pathway in diabetic complications,Bladder cancer,Estrogen signaling pathway,HIF-1 signaling pathway.Conclusion:Zhitong rushen decoction for the treatment of functional anorectal pain may be related to its multi-component effect on multiple targets and multiple signaling pathways,providing theoretical basis for further study of active ingredients and mechanism of action.
