Due to the large number of finite element mesh generated,it is difficult to use full-scale model to simulate largesection underground engineering,especially considering the coupling effect.A regional model is attempte...Due to the large number of finite element mesh generated,it is difficult to use full-scale model to simulate largesection underground engineering,especially considering the coupling effect.A regional model is attempted to achieve this simulation.A variable boundary condition method for hybrid regional model is proposed to realize the numerical simulation of large-section tunnel construction.Accordingly,the balance of initial ground stress under asymmetric boundary conditions achieves by applying boundary conditions step by step with secondary development ofDynaflowscripts,which is the key issue of variable boundary conditionmethod implementation.In this paper,Gongbei tunnel based on hybrid regional model involvingmulti-field coupling is simulated.Meanwhile,the variable boundary condition method for regional model is verified against model initialization and the ground deformation due to tunnel excavation is predicted via the proposed hybrid regional model.Compared with the monitoring data of actual engineering,the results indicated that the hybrid regional model has a good prediction effect.展开更多
Freeze-sealing pipe roof method is applied in the Gongbei tunnel,which causes the ground surface uplift induced by frost heave.A frost heaving prediction approach based on the coefficient of cold expansion is proposed...Freeze-sealing pipe roof method is applied in the Gongbei tunnel,which causes the ground surface uplift induced by frost heave.A frost heaving prediction approach based on the coefficient of cold expansion is proposed to simulate the ground deformation of the Gongbei tunnel.The coefficient of cold expansion in the model and the frost heaving rate from the frost heave test under the hydration condition can achieve a good correspondence making the calculation result closer to the actual engineering.The ground surface uplift along the lateral and longitudinal direction are respectively analyzed and compared with the field measured data to validate the model.The results show that a good agreement between the frost heaving prediction model and the field measured data verifies the rationality and applicability of the proposed model.The maximum uplift of the Gongbei tunnel appears at the center of the model,gradually decreasing along with the lateral and longitudinal directions.The curve in the lateral direction presents a normal distribution due to the influence of the constraint of two sides,while the one along the lateral direction shapes like a parabola with the opening downward due to the temperature field distribution.The model provides a reference for frost heaving engineering calculation.展开更多
Soil selenium(Se)deficiency is a major contributor to hidden hunger worldwide,and exogenous Se fertilization is effective to increase the Se content in wheat grains.However,the mechanisms by which Se biotransformation...Soil selenium(Se)deficiency is a major contributor to hidden hunger worldwide,and exogenous Se fertilization is effective to increase the Se content in wheat grains.However,the mechanisms by which Se biotransformation within plants regulates starch synthesis and shapes starch composition during grain development remain poorly understood.This study systematically elucidated the biotransformation of Se and its relationship with starch biosynthesis in wheat grains at the early-milk,soft-dough,and mature stages under sodium selenite(Na_(2)SeO_(3))fertilization with pot experiments,and investigated the dose-dependent effects of Se application(0-20.0 mg kg^(-1))on Se uptake and biotransformation in wheat tissues.The results indicated that upregulated expression of TaCS and TaHMT promoted the transformation of supplied SeO_(3)^(2-)into organic speciation.Upregulation of TaAGPS1,TaSBE1,TaSBE2 and TaSSI increased the amylopectin content and amylopectin/amylose ratio in wheat grains.Upon Se fertilization at 5.0 mg kg^(-1),the selenomethionine(SeMet)content reached 7.08 mg kg^(-1)and the amylopectin content increased by 3.6%,excessive application(20.0 mg kg^(-1))significantly reduced grain yield.Additionally,the milk stage was identified as the critical stage for rapid Se accumulation and starch remodeling.Overall,this study provides a conceptual advance by linking Se biotransformation with starch synthesis regulation in developing wheat grains,offering a mechanistic foundation for optimizing stage-specific Se fertilization strategies to enhance grain nutritional quality and support the development of Se-enriched functional wheat-based foods.展开更多
基金supported by the financial support from National Natural Sci-ence Foundation of China(No.51478340)Natural Science Foundation of Jiangsu Province(No.BK20200707)+2 种基金Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.20KJB560029)China Postdoctoral Science Foundation(No.2020M671670)Key Laboratory of Soft Soils and Geoenvironmental Engineering(Zhejiang University),Ministry of Education(No.2020P04).
文摘Due to the large number of finite element mesh generated,it is difficult to use full-scale model to simulate largesection underground engineering,especially considering the coupling effect.A regional model is attempted to achieve this simulation.A variable boundary condition method for hybrid regional model is proposed to realize the numerical simulation of large-section tunnel construction.Accordingly,the balance of initial ground stress under asymmetric boundary conditions achieves by applying boundary conditions step by step with secondary development ofDynaflowscripts,which is the key issue of variable boundary conditionmethod implementation.In this paper,Gongbei tunnel based on hybrid regional model involvingmulti-field coupling is simulated.Meanwhile,the variable boundary condition method for regional model is verified against model initialization and the ground deformation due to tunnel excavation is predicted via the proposed hybrid regional model.Compared with the monitoring data of actual engineering,the results indicated that the hybrid regional model has a good prediction effect.
基金supported by the financial support from National Natural Science Foundation of China(No.51478340)Natural Science Foundation of Jiangsu Province(No.BK20200707)+4 种基金The Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.20KJB560029)China Postdoctoral Science Foundation(No.2020M671670)Key Laboratory of Soft Soils and Geoenvironmental Engineering(Zhejiang University)Ministry of Education(No.2020P04)the support above is gratefully acknowledged.
文摘Freeze-sealing pipe roof method is applied in the Gongbei tunnel,which causes the ground surface uplift induced by frost heave.A frost heaving prediction approach based on the coefficient of cold expansion is proposed to simulate the ground deformation of the Gongbei tunnel.The coefficient of cold expansion in the model and the frost heaving rate from the frost heave test under the hydration condition can achieve a good correspondence making the calculation result closer to the actual engineering.The ground surface uplift along the lateral and longitudinal direction are respectively analyzed and compared with the field measured data to validate the model.The results show that a good agreement between the frost heaving prediction model and the field measured data verifies the rationality and applicability of the proposed model.The maximum uplift of the Gongbei tunnel appears at the center of the model,gradually decreasing along with the lateral and longitudinal directions.The curve in the lateral direction presents a normal distribution due to the influence of the constraint of two sides,while the one along the lateral direction shapes like a parabola with the opening downward due to the temperature field distribution.The model provides a reference for frost heaving engineering calculation.
基金supported by the National Natural Science Foundation of China(Grant Nos.42477023 and 42077133)the National Key Research and Development Program of China(Grant No.2023YFC3709804-01)+1 种基金the HZAU-AGIS cooperation Fund(Grant No.SZYJY2022035)Hubei Hongshan Laboratory for financial support.
文摘Soil selenium(Se)deficiency is a major contributor to hidden hunger worldwide,and exogenous Se fertilization is effective to increase the Se content in wheat grains.However,the mechanisms by which Se biotransformation within plants regulates starch synthesis and shapes starch composition during grain development remain poorly understood.This study systematically elucidated the biotransformation of Se and its relationship with starch biosynthesis in wheat grains at the early-milk,soft-dough,and mature stages under sodium selenite(Na_(2)SeO_(3))fertilization with pot experiments,and investigated the dose-dependent effects of Se application(0-20.0 mg kg^(-1))on Se uptake and biotransformation in wheat tissues.The results indicated that upregulated expression of TaCS and TaHMT promoted the transformation of supplied SeO_(3)^(2-)into organic speciation.Upregulation of TaAGPS1,TaSBE1,TaSBE2 and TaSSI increased the amylopectin content and amylopectin/amylose ratio in wheat grains.Upon Se fertilization at 5.0 mg kg^(-1),the selenomethionine(SeMet)content reached 7.08 mg kg^(-1)and the amylopectin content increased by 3.6%,excessive application(20.0 mg kg^(-1))significantly reduced grain yield.Additionally,the milk stage was identified as the critical stage for rapid Se accumulation and starch remodeling.Overall,this study provides a conceptual advance by linking Se biotransformation with starch synthesis regulation in developing wheat grains,offering a mechanistic foundation for optimizing stage-specific Se fertilization strategies to enhance grain nutritional quality and support the development of Se-enriched functional wheat-based foods.
