Carbide slag was used as an activator to improve the activity of anhydrous phosphogypsum.Carbide slag could greatly improve the mechanical strength of anhydrous phosphogypsum than K_(2)SO_(4).The compressive strength ...Carbide slag was used as an activator to improve the activity of anhydrous phosphogypsum.Carbide slag could greatly improve the mechanical strength of anhydrous phosphogypsum than K_(2)SO_(4).The compressive strength of 11 wt%carbide slag and 1 wt%K_(2)SO_(4)activated anhydrous phosphogypsum increased greatly to 8.6 MPa at 3 d,and 11.9 MPa at 7 d,and 16.0 MPa at 28 d,respectively.The rate of hydration heat was accelerated and the total hydration heat was increased,and more calcium sulfate dihydrate was formed and cross-linked with other parts which improved the compressive strength of anhydrous phosphogypsum under the effects of different activators.It was indicated that carbide slag was a highly effective and cost-efficient activator.The result provides a highly effective and low-cost method which results in a novel and high value-added method for the utilization of phosphogypsum in the future.展开更多
The phosphorus slag（PS） can be used as a supplementary cementitious material due to its potential hydrating activity. However, its usage has been limited by its adverse effects, including prolonged setting and lower...The phosphorus slag（PS） can be used as a supplementary cementitious material due to its potential hydrating activity. However, its usage has been limited by its adverse effects, including prolonged setting and lowered early-stage strength. In this study, we achieved ultrafine granulation of PS using wetmilling（reducing d50 to as low as 2.02 μm） in order to increase its activity, and examined the physico-chemical properties of the resulting materials, including particle-size distribution, slurry pH, zeta potential, and activity index, as well as how their replacement level and granularity affect the setting time and mechanical performance of PS-cement mixture systems. The results suggested that as the granularity increases, there are significant boosts in the uniformity of particle sizes, slurry pH, and activity index, and the effects on cement paste, including setting times, and early-and late-stage strengths, are significantly mitigated. When d（50）=2.02 μm, the slurry becomes strongly alkaline（pH=12.16） compared to the initial d（50）=20.75 μm（pH=9.49）, and the activity is increased by 73%; when used at 40% replacement, the PS-cement mixture system can reach a 28 d compressive strength of 93.2 MPa, 36% higher than that of the pure cement control group.展开更多
Thaumasite form of sulfate attack（TSA） can be observed in cement containing limestone under sulfate condition at low temperature. Mixing with suitable mineral admixture could be a good choice to improve the TSA resi...Thaumasite form of sulfate attack（TSA） can be observed in cement containing limestone under sulfate condition at low temperature. Mixing with suitable mineral admixture could be a good choice to improve the TSA resistance performance of cement-based materials. We investigated the durability performance of limestone-cement mortars reinforced with silica fume（SF） in 5% MgSO_4 solution at 5 ℃. The mortars, which were immersed in aggressive condition, were prepared with 2%, 4%, 6%, 8%, and 10% cement replacement by SF at a fixed water-to-binder ratio. Appearance, compressive strength, change of length and mass and corrosion products were investigated to evaluate the TSA resistance performance of SF based specimens. The results showed that specimens in the absence of SF almost disintegrated. Increasing SF dosage can reduce the degree of deterioration of SF mortars in TSA environment. Mortar mixtures with more than 6% SF merely show slight degeneration in relation to macroscopic and microscopic tests and characterizations.展开更多
目的:评价A群C群脑膜炎球菌多糖结合疫苗(group A and group C meningococcal polysaccharide conjugate vaccine,MPCV-AC)和乙型肝炎疫苗(hepatitis B vaccine,HepB)同时接种后的安全性。方法:通过国家免疫规划信息系统和安徽省免疫规...目的:评价A群C群脑膜炎球菌多糖结合疫苗(group A and group C meningococcal polysaccharide conjugate vaccine,MPCV-AC)和乙型肝炎疫苗(hepatitis B vaccine,HepB)同时接种后的安全性。方法:通过国家免疫规划信息系统和安徽省免疫规划信息管理系统分别收集2020年至2022年安徽省适龄儿童MPCV-AC和HepB的疑似预防接种异常反应(adverse events following immunization,AEFI)数据和预防接种数据,比较2种疫苗同时接种和单独接种的AEFI的发生风险。结果:MPCV-AC第1剂次和HepB第3剂次同时接种、MPCV-AC第1剂次单独接种、HepB第3剂次单独接种的AEFI报告发生率分别为48.03/10万(280例)、56.37/10万(314例)、51.96/10万(283例);其中一般反应分别为43.91/10万(256例)、51.35/10万(286例)、48.65/10万(265例),异常反应分别为4.12/10万(24例)、4.85/10万(27例)、3.30/10万(18例)。同时接种组、单独接种组的AEFI发生风险、一般反应及异常反应的发生风险差异均无统计学意义。结论:MPCV-AC和HepB同时接种未增加AEFI的发生风险,可作为6月龄儿童同时接种MPCV-AC和HepB的科学依据。展开更多
针对跟踪复杂机动目标过程中由于目标运动状态发生变化导致的跟踪误差较大的问题,提出一种自适应交互多模型无迹卡尔曼滤波(interacting multiple model unscented Kalman filter,IMM-UKF)算法,使用模型概率后验信息和模型似然函数自适...针对跟踪复杂机动目标过程中由于目标运动状态发生变化导致的跟踪误差较大的问题,提出一种自适应交互多模型无迹卡尔曼滤波(interacting multiple model unscented Kalman filter,IMM-UKF)算法,使用模型概率后验信息和模型似然函数自适应修正马尔可夫转移概率矩阵(transition probability matrix,TPM)。设计模型概率校正方法和模型转移加速方法,两种方法分别作用于模型稳定阶段和模型转移阶段,提高模型概率准确度和模型转移响应速度,减小状态估计误差。最后,通过两种场景下的实验验证所提算法在目标具有复杂运动状态下的性能,并与传统方法进行对比分析,在目标做机动运动时,位置精度和速度精度分别提高了15%和26%,验证了算法的有效性和可行性。展开更多
基金Funded by Innovation Group Fund Project of Hubei Province(No.2020CFA039)the Key Research and Development Program of Hubei Province(No.2020BCA077)。
文摘Carbide slag was used as an activator to improve the activity of anhydrous phosphogypsum.Carbide slag could greatly improve the mechanical strength of anhydrous phosphogypsum than K_(2)SO_(4).The compressive strength of 11 wt%carbide slag and 1 wt%K_(2)SO_(4)activated anhydrous phosphogypsum increased greatly to 8.6 MPa at 3 d,and 11.9 MPa at 7 d,and 16.0 MPa at 28 d,respectively.The rate of hydration heat was accelerated and the total hydration heat was increased,and more calcium sulfate dihydrate was formed and cross-linked with other parts which improved the compressive strength of anhydrous phosphogypsum under the effects of different activators.It was indicated that carbide slag was a highly effective and cost-efficient activator.The result provides a highly effective and low-cost method which results in a novel and high value-added method for the utilization of phosphogypsum in the future.
基金Funded by National Natural Science Foundation of China(No.51372076)the Technology Innovation Major Project of Hubei Province(No.2017ACA178)the Science and Technology Support Program of Hubei Province(No.2015BCA244)
文摘The phosphorus slag（PS） can be used as a supplementary cementitious material due to its potential hydrating activity. However, its usage has been limited by its adverse effects, including prolonged setting and lowered early-stage strength. In this study, we achieved ultrafine granulation of PS using wetmilling（reducing d50 to as low as 2.02 μm） in order to increase its activity, and examined the physico-chemical properties of the resulting materials, including particle-size distribution, slurry pH, zeta potential, and activity index, as well as how their replacement level and granularity affect the setting time and mechanical performance of PS-cement mixture systems. The results suggested that as the granularity increases, there are significant boosts in the uniformity of particle sizes, slurry pH, and activity index, and the effects on cement paste, including setting times, and early-and late-stage strengths, are significantly mitigated. When d（50）=2.02 μm, the slurry becomes strongly alkaline（pH=12.16） compared to the initial d（50）=20.75 μm（pH=9.49）, and the activity is increased by 73%; when used at 40% replacement, the PS-cement mixture system can reach a 28 d compressive strength of 93.2 MPa, 36% higher than that of the pure cement control group.
基金Funded by Hubei Provincial Natural Science Foundation of China(No.2016CFB353)the Science and Technology Support Program of Hubei Province(No.2015BCA244)National Natural Science Foundation of China(No.51372076)
文摘Thaumasite form of sulfate attack（TSA） can be observed in cement containing limestone under sulfate condition at low temperature. Mixing with suitable mineral admixture could be a good choice to improve the TSA resistance performance of cement-based materials. We investigated the durability performance of limestone-cement mortars reinforced with silica fume（SF） in 5% MgSO_4 solution at 5 ℃. The mortars, which were immersed in aggressive condition, were prepared with 2%, 4%, 6%, 8%, and 10% cement replacement by SF at a fixed water-to-binder ratio. Appearance, compressive strength, change of length and mass and corrosion products were investigated to evaluate the TSA resistance performance of SF based specimens. The results showed that specimens in the absence of SF almost disintegrated. Increasing SF dosage can reduce the degree of deterioration of SF mortars in TSA environment. Mortar mixtures with more than 6% SF merely show slight degeneration in relation to macroscopic and microscopic tests and characterizations.
文摘目的:评价A群C群脑膜炎球菌多糖结合疫苗(group A and group C meningococcal polysaccharide conjugate vaccine,MPCV-AC)和乙型肝炎疫苗(hepatitis B vaccine,HepB)同时接种后的安全性。方法:通过国家免疫规划信息系统和安徽省免疫规划信息管理系统分别收集2020年至2022年安徽省适龄儿童MPCV-AC和HepB的疑似预防接种异常反应(adverse events following immunization,AEFI)数据和预防接种数据,比较2种疫苗同时接种和单独接种的AEFI的发生风险。结果:MPCV-AC第1剂次和HepB第3剂次同时接种、MPCV-AC第1剂次单独接种、HepB第3剂次单独接种的AEFI报告发生率分别为48.03/10万(280例)、56.37/10万(314例)、51.96/10万(283例);其中一般反应分别为43.91/10万(256例)、51.35/10万(286例)、48.65/10万(265例),异常反应分别为4.12/10万(24例)、4.85/10万(27例)、3.30/10万(18例)。同时接种组、单独接种组的AEFI发生风险、一般反应及异常反应的发生风险差异均无统计学意义。结论:MPCV-AC和HepB同时接种未增加AEFI的发生风险,可作为6月龄儿童同时接种MPCV-AC和HepB的科学依据。
文摘针对跟踪复杂机动目标过程中由于目标运动状态发生变化导致的跟踪误差较大的问题,提出一种自适应交互多模型无迹卡尔曼滤波(interacting multiple model unscented Kalman filter,IMM-UKF)算法,使用模型概率后验信息和模型似然函数自适应修正马尔可夫转移概率矩阵(transition probability matrix,TPM)。设计模型概率校正方法和模型转移加速方法,两种方法分别作用于模型稳定阶段和模型转移阶段,提高模型概率准确度和模型转移响应速度,减小状态估计误差。最后,通过两种场景下的实验验证所提算法在目标具有复杂运动状态下的性能,并与传统方法进行对比分析,在目标做机动运动时,位置精度和速度精度分别提高了15%和26%,验证了算法的有效性和可行性。
