During the excavation and support process in deep soft rocks,complex conditions such as high stress and strong disturbance can be encountered.The complex conditions can cause failure of the support system.Aiming at st...During the excavation and support process in deep soft rocks,complex conditions such as high stress and strong disturbance can be encountered.The complex conditions can cause failure of the support system.Aiming at stability control in deep soft rocks,we proposed the excavation compensation theory.A new high strength and high toughness material was developed.The breaking load and elongation of the new material are 1.59 and 1.78 times that of common bolt materials.To overcome the problem that the CABLE element in FLAC^(3D) cannot simulate failure of support structures,the numerical model for the whole process of force-breaking-anchorage failure simulation(FBAS)for bolts(cables)was established.The numerical experiments on the excavation compensation control of deep soft rock were carried out.The excavation compensation control mechanism of high strength and high toughness material was clarified.Compared with the common support scheme,the highly prestressed support has a maximum increase of 90.24%in radial stress compensation rate and a maximum increase of 67.85%in deformation control rate.The results illustrate the rationality of the excavation compensation theory.The compensation design method of excavations in deep soft rocks was proposed and applied in a deep soft rock chamber.The monitoring indicated that the maximum surrounding rock deformation is 180 mm,reduced by 64%compared to the common support.The deformation of the chamber was controlled and the surrounding rock was stable.展开更多
亚马逊的跨境电商物流FBA(Fulfillment by Amazon)模式是当今电子商务领域的一项创新实践,其为全球卖家提供了仓储、打包、配送及客服等一站式服务。本文旨在深入评价FBA模式在跨境电商物流中的应用现状,分析其优势与局限性,并基于此提...亚马逊的跨境电商物流FBA(Fulfillment by Amazon)模式是当今电子商务领域的一项创新实践,其为全球卖家提供了仓储、打包、配送及客服等一站式服务。本文旨在深入评价FBA模式在跨境电商物流中的应用现状,分析其优势与局限性,并基于此提出策略优化建议,通过对FBA模式的综合评价,我们发现其不仅能够帮助卖家降低物流成本、提高配送效率,还能增强消费者的购物体验。展开更多
The Chinese Academy of Sciences(CAS)launched the Big Earth Data Science Engineering Program(CASEarth)in 2018,which laid the foundation for the International Research Center of Big Data for Sustainable Development Goal...The Chinese Academy of Sciences(CAS)launched the Big Earth Data Science Engineering Program(CASEarth)in 2018,which laid the foundation for the International Research Center of Big Data for Sustainable Development Goals(CBAS).Building on CASEarth’s achievements,CBAS integrates advanced digital technologies to advance the UN Sustainable Development Goals(SDGs)through five key missions:(1)developing SDG data infrastructure and information products via its SDG Big Data Platform,utilizing advanced computing,cloud services,and AI;(2)developing and launching a series of SDG satellites,including SDGSAT-1,which provides crucial Earth observation data through its Open Science Program;(3)providing new knowledge for SDG monitoring and evaluation through annual reports(Big Earth Data in Support of the Sustainable Development Goals,published since 2019)and guiding the development of big data-driven technical solutions and theoretical systems;(4)establishing a think tank for science,technology,and innovation,promoting SDGs through initiatives like the annual International Forum on Big Data for Sustainable Development Goals(FBAS)and the CBAS Fellowship Program;and(5)providing capacity development for SDGs in developing countries through international collaborations,such as the Digital Belt and Road Program(DBAR),which offers professional education and training in big data.Future CBAS efforts will focus on expanding data access,enhancing AI capabilities for SDG indicator monitoring,and strengthening international partnerships to address data gaps and ensure equitable access to technology and expertise for achieving global sustainability.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2023YFC3805700)the National Natural Science Foundation of China(Grant No.42277174)the Fundamental Research Funds for the Central Universities,China(Grant No.2024JCCXSB01).
文摘During the excavation and support process in deep soft rocks,complex conditions such as high stress and strong disturbance can be encountered.The complex conditions can cause failure of the support system.Aiming at stability control in deep soft rocks,we proposed the excavation compensation theory.A new high strength and high toughness material was developed.The breaking load and elongation of the new material are 1.59 and 1.78 times that of common bolt materials.To overcome the problem that the CABLE element in FLAC^(3D) cannot simulate failure of support structures,the numerical model for the whole process of force-breaking-anchorage failure simulation(FBAS)for bolts(cables)was established.The numerical experiments on the excavation compensation control of deep soft rock were carried out.The excavation compensation control mechanism of high strength and high toughness material was clarified.Compared with the common support scheme,the highly prestressed support has a maximum increase of 90.24%in radial stress compensation rate and a maximum increase of 67.85%in deformation control rate.The results illustrate the rationality of the excavation compensation theory.The compensation design method of excavations in deep soft rocks was proposed and applied in a deep soft rock chamber.The monitoring indicated that the maximum surrounding rock deformation is 180 mm,reduced by 64%compared to the common support.The deformation of the chamber was controlled and the surrounding rock was stable.
文摘亚马逊的跨境电商物流FBA(Fulfillment by Amazon)模式是当今电子商务领域的一项创新实践,其为全球卖家提供了仓储、打包、配送及客服等一站式服务。本文旨在深入评价FBA模式在跨境电商物流中的应用现状,分析其优势与局限性,并基于此提出策略优化建议,通过对FBA模式的综合评价,我们发现其不仅能够帮助卖家降低物流成本、提高配送效率,还能增强消费者的购物体验。
文摘The Chinese Academy of Sciences(CAS)launched the Big Earth Data Science Engineering Program(CASEarth)in 2018,which laid the foundation for the International Research Center of Big Data for Sustainable Development Goals(CBAS).Building on CASEarth’s achievements,CBAS integrates advanced digital technologies to advance the UN Sustainable Development Goals(SDGs)through five key missions:(1)developing SDG data infrastructure and information products via its SDG Big Data Platform,utilizing advanced computing,cloud services,and AI;(2)developing and launching a series of SDG satellites,including SDGSAT-1,which provides crucial Earth observation data through its Open Science Program;(3)providing new knowledge for SDG monitoring and evaluation through annual reports(Big Earth Data in Support of the Sustainable Development Goals,published since 2019)and guiding the development of big data-driven technical solutions and theoretical systems;(4)establishing a think tank for science,technology,and innovation,promoting SDGs through initiatives like the annual International Forum on Big Data for Sustainable Development Goals(FBAS)and the CBAS Fellowship Program;and(5)providing capacity development for SDGs in developing countries through international collaborations,such as the Digital Belt and Road Program(DBAR),which offers professional education and training in big data.Future CBAS efforts will focus on expanding data access,enhancing AI capabilities for SDG indicator monitoring,and strengthening international partnerships to address data gaps and ensure equitable access to technology and expertise for achieving global sustainability.
