β-hemihydrate phosphogypsum(HPG)was used to replace a part of cement to prepare hemihydrate phosphogypsum-red mud concrete,effectively increasing the comprehensive use of red mud(RM)and HPG in the concrete.The effect...β-hemihydrate phosphogypsum(HPG)was used to replace a part of cement to prepare hemihydrate phosphogypsum-red mud concrete,effectively increasing the comprehensive use of red mud(RM)and HPG in the concrete.The effects of different RM and HPG contents on the flow properties,water absorption and strengths of HPG-RM concretes were investigated.The appropriate content of HPG reduces the water resistance of red mud concrete,enhances the cohesion and water retention,and effectively filled the pores to decrease the degree of free water erosion.The optimal HPG content was 5%,10%,and 10%for red mud concretes with 30%,40%,and 50%RM,respectively.HPG content has more significant effects on the 28 d strengths of HPG-RM concretes.This consequence is accordant with the effect of HPG content on the pore size and pore size distribution from MIP results.The SEM and XRD results show that a large amount of SO_(4)^(2-)and Ca^(2+)from HPG promote the volcanic ash effect of RM generating more favorable hydration products.However,excessive HPG generates more Ettringite to inhibit the generation of calcium silicate and albite,causing cracks in the concrete and deteriorating performance.展开更多
The dynamics of spin–orbit-coupled Bose–Einstein condensate with parity-time symmetry through a moving obstacle potential is simulated numerically. In the miscible two-component condensate, the formation of the K...The dynamics of spin–orbit-coupled Bose–Einstein condensate with parity-time symmetry through a moving obstacle potential is simulated numerically. In the miscible two-component condensate, the formation of the Kármán vortex street is observed in one component, while ‘the half-quantum vortex street' is observed in the other component. Other patterns of vortex shedding, such as oblique vortex dipoles, V-shaped vortex pairs, irregular turbulence, and combined modes of various wakes, can also be found. The ratio of inter-vortex spacing in one row to the distance between vortex rows is approximately0.18, which is less than the stability condition 0.28 of classical fluid. The drag force acting on the obstacle potential is simulated. The parametric regions of Kármán vortex street and other vortex patterns are calculated. The range of Kármán vortex street is surrounded by the region of combined modes. In addition, spin–orbit coupling disrupts the symmetry of the system and the gain-loss affects the local particle distribution of the system, which leads to the local symmetry breaking of the system, and finally influences the stability of the Kármán vortex street. Finally, we propose an experimental protocol to realize the Kármán vortex street in a system.展开更多
BACKGROUND The use of uncemented cups during total hip arthroplasty(THA)has gained popularity in recent years.The Robert Mathys(RM)pressfit cup,an uncemented monoblock implant is expected to preserve bone density due ...BACKGROUND The use of uncemented cups during total hip arthroplasty(THA)has gained popularity in recent years.The Robert Mathys(RM)pressfit cup,an uncemented monoblock implant is expected to preserve bone density due to its composition and external surface,while reducing backside wear with its monoblock construction.These factors should lead to a high survival rate of the implant.AIM To evaluate the mid-term survival and functional outcome of the RM Pressfit cup in a large study population.METHODS Between 2011 and 2020,we included 1324 patients receiving a primary THA using the RM pressfit cup.Final clinical follow-up was performed at 2 years postoperatively with the Dutch arthroplasty register used to assess implant status thereafter.Revision for acetabular failure and reason for revision were reported to evaluate implant survival,while the hip disability and osteoarthritis outcome score(HOOS)scores were used to assess functional outcome.RESULTS The mean age at surgery was 64.9 years.The mean follow-up was 4.6 years.Of the 1324 THAs performed,13 needed cup revisions within 5 years after index THA:5 due to aseptic loosening,6 due to infection,2 due to dislocation and 2 due to other causes.This resulted in a 5-year cup survival of 98.8%(95%CI:98.1-99.5).Nine of the cup revisions occurred within the first year after index THA.HOOS scores increased significantly in all domains during the first year and levelled out during the second year.CONCLUSION In the present study,the RM pressfit cup demonstrated excellent clinical outcomes at mid-term follow-up;however,future studies are needed to assess the long-term outcomes of this acetabular implant.展开更多
Due to the issue of long-horizon,a substantial number of visits to the state space is required during the exploration phase of reinforcement learning(RL)to gather valuable information.Addi-tionally,due to the challeng...Due to the issue of long-horizon,a substantial number of visits to the state space is required during the exploration phase of reinforcement learning(RL)to gather valuable information.Addi-tionally,due to the challenge posed by sparse rewards,the planning phase of reinforcement learning consumes a considerable amount of time on repetitive and unproductive tasks before adequately ac-cessing sparse reward signals.To address these challenges,this work proposes a space partitioning and reverse merging(SPaRM)framework based on reward-free exploration(RFE).The framework consists of two parts:the space partitioning module and the reverse merging module.The former module partitions the entire state space into a specific number of subspaces to expedite the explora-tion phase.This work establishes its theoretical sample complexity lower bound.The latter module starts planning in reverse from near the target and gradually extends to the starting state,as opposed to the conventional practice of starting at the beginning.This facilitates the early involvement of sparse rewards at the target in the policy update process.This work designs two experimental envi-ronments:a complex maze and a set of randomly generated maps.Compared with two state-of-the-art(SOTA)algorithms,experimental results validate the effectiveness and superior performance of the proposed algorithm.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.52168027 and 12362011)the Guizhou Province Science and Technology Innovation Talent Team Project(No.CXTD[2023]022)the Guizhou Province Science and Technology Support Project(No.[2022]027)。
文摘β-hemihydrate phosphogypsum(HPG)was used to replace a part of cement to prepare hemihydrate phosphogypsum-red mud concrete,effectively increasing the comprehensive use of red mud(RM)and HPG in the concrete.The effects of different RM and HPG contents on the flow properties,water absorption and strengths of HPG-RM concretes were investigated.The appropriate content of HPG reduces the water resistance of red mud concrete,enhances the cohesion and water retention,and effectively filled the pores to decrease the degree of free water erosion.The optimal HPG content was 5%,10%,and 10%for red mud concretes with 30%,40%,and 50%RM,respectively.HPG content has more significant effects on the 28 d strengths of HPG-RM concretes.This consequence is accordant with the effect of HPG content on the pore size and pore size distribution from MIP results.The SEM and XRD results show that a large amount of SO_(4)^(2-)and Ca^(2+)from HPG promote the volcanic ash effect of RM generating more favorable hydration products.However,excessive HPG generates more Ettringite to inhibit the generation of calcium silicate and albite,causing cracks in the concrete and deteriorating performance.
基金supported by the National Key R&D Program of China[grant number 2022YFF0801301]the National Natural Science Foundation of China[grant number 41575033]+1 种基金the Fengyun Satellite Application Pioneer Project[grant number FY-APP-2022.0111]the Natural Science Foundation of Jiangsu Province[grant number BK20231148]。
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12065022 and 12147213)。
文摘The dynamics of spin–orbit-coupled Bose–Einstein condensate with parity-time symmetry through a moving obstacle potential is simulated numerically. In the miscible two-component condensate, the formation of the Kármán vortex street is observed in one component, while ‘the half-quantum vortex street' is observed in the other component. Other patterns of vortex shedding, such as oblique vortex dipoles, V-shaped vortex pairs, irregular turbulence, and combined modes of various wakes, can also be found. The ratio of inter-vortex spacing in one row to the distance between vortex rows is approximately0.18, which is less than the stability condition 0.28 of classical fluid. The drag force acting on the obstacle potential is simulated. The parametric regions of Kármán vortex street and other vortex patterns are calculated. The range of Kármán vortex street is surrounded by the region of combined modes. In addition, spin–orbit coupling disrupts the symmetry of the system and the gain-loss affects the local particle distribution of the system, which leads to the local symmetry breaking of the system, and finally influences the stability of the Kármán vortex street. Finally, we propose an experimental protocol to realize the Kármán vortex street in a system.
文摘BACKGROUND The use of uncemented cups during total hip arthroplasty(THA)has gained popularity in recent years.The Robert Mathys(RM)pressfit cup,an uncemented monoblock implant is expected to preserve bone density due to its composition and external surface,while reducing backside wear with its monoblock construction.These factors should lead to a high survival rate of the implant.AIM To evaluate the mid-term survival and functional outcome of the RM Pressfit cup in a large study population.METHODS Between 2011 and 2020,we included 1324 patients receiving a primary THA using the RM pressfit cup.Final clinical follow-up was performed at 2 years postoperatively with the Dutch arthroplasty register used to assess implant status thereafter.Revision for acetabular failure and reason for revision were reported to evaluate implant survival,while the hip disability and osteoarthritis outcome score(HOOS)scores were used to assess functional outcome.RESULTS The mean age at surgery was 64.9 years.The mean follow-up was 4.6 years.Of the 1324 THAs performed,13 needed cup revisions within 5 years after index THA:5 due to aseptic loosening,6 due to infection,2 due to dislocation and 2 due to other causes.This resulted in a 5-year cup survival of 98.8%(95%CI:98.1-99.5).Nine of the cup revisions occurred within the first year after index THA.HOOS scores increased significantly in all domains during the first year and levelled out during the second year.CONCLUSION In the present study,the RM pressfit cup demonstrated excellent clinical outcomes at mid-term follow-up;however,future studies are needed to assess the long-term outcomes of this acetabular implant.
基金Supported by the International Partnership Program of Chinese Academy of Sciences(No.184131KYSB20200033).
文摘Due to the issue of long-horizon,a substantial number of visits to the state space is required during the exploration phase of reinforcement learning(RL)to gather valuable information.Addi-tionally,due to the challenge posed by sparse rewards,the planning phase of reinforcement learning consumes a considerable amount of time on repetitive and unproductive tasks before adequately ac-cessing sparse reward signals.To address these challenges,this work proposes a space partitioning and reverse merging(SPaRM)framework based on reward-free exploration(RFE).The framework consists of two parts:the space partitioning module and the reverse merging module.The former module partitions the entire state space into a specific number of subspaces to expedite the explora-tion phase.This work establishes its theoretical sample complexity lower bound.The latter module starts planning in reverse from near the target and gradually extends to the starting state,as opposed to the conventional practice of starting at the beginning.This facilitates the early involvement of sparse rewards at the target in the policy update process.This work designs two experimental envi-ronments:a complex maze and a set of randomly generated maps.Compared with two state-of-the-art(SOTA)algorithms,experimental results validate the effectiveness and superior performance of the proposed algorithm.
