In this paper, the generalized variational principle of dynamic analysis for the blast-resistant underground structures is established, and the corresponding generalized functional of elastoplastic analysis for underg...In this paper, the generalized variational principle of dynamic analysis for the blast-resistant underground structures is established, and the corresponding generalized functional of elastoplastic analysis for underground structures is derived, and the generalized variational principle of nonconservative system is given, thus the fundamental of dynamical analysis for underground structures to resist blast is proposed. Finally, for the underground cylindrical structure to resist blast, dynamical calculations are made, and compared with the test results.展开更多
The structural deformation velocity plays a significant role in the dynamic calculation of underground blast-resistant structures. The motion differentiating equation of a structure system taking into account the role...The structural deformation velocity plays a significant role in the dynamic calculation of underground blast-resistant structures. The motion differentiating equation of a structure system taking into account the role of deformation velocity of the structure will truthfully describe the actual situation of structural vibration. With the one-dimensional plane wave theory, the expression of load on the structural periphery is developed, and the generalized variation principle for the dynamic analysis of underground arched-bar structures is given. At the same time, the results of the numerical calculation are compared.展开更多
Shuangchao 25 was derived from the cross ofShuanggui 36/Kang 2 in 1983.The female parentwas a panicle-number type with quick growth andstrong-tiUering ability.The male parent was apanicle-weight type with Bl and BB re...Shuangchao 25 was derived from the cross ofShuanggui 36/Kang 2 in 1983.The female parentwas a panicle-number type with quick growth andstrong-tiUering ability.The male parent was apanicle-weight type with Bl and BB resistance.The segregated progenies were selected by the"Method of Combination and Population Selec-展开更多
In this paper,UR50 ultra-early-strength cement-based self-compacting high-strength concrete slabs(URCS)have been subjected to contact explosion tests with different TNT charge quality,aiming to evaluate the anti-explo...In this paper,UR50 ultra-early-strength cement-based self-compacting high-strength concrete slabs(URCS)have been subjected to contact explosion tests with different TNT charge quality,aiming to evaluate the anti-explosive performance of URCS.In the experiment,three kinds of ultra-early-strength cement-based reinforced concrete slabs with different reinforcement ratios and a normal concrete slab(NRCS)were used as the control specimen,the curing time of URCS is 28 days and 24 h respectively.The research results show that URCS has a stronger anti-explosion ability than NRCS.The failure mode of URCS under contact explosion is that the front of the reinforced concrete slab explodes into a crater,and the back is spall.With the increase of the charge,the failure mode of the reinforced concrete slab gradually changed to explosive penetration and explosive punching.The experiment results also show that the reinforcement ratio of URCS has little effect on the anti-blast performance,and URCS can reach its anti-blast performance at 28 days after curing for 24 h.On this basis,the damage parameters of URCS for different curing durations were quantified,and an empirical formula for predicting the diameter of the crater and spalling was established.展开更多
目的利用医疗大数据和机器学习技术相结合,探索基于临床结果的临床医师绩效评价方法。方法采用非负主成分分析法(non-negative principal component analysis,NPCA),基于非负稀疏主成分算法(non-negative sparse principal component an...目的利用医疗大数据和机器学习技术相结合,探索基于临床结果的临床医师绩效评价方法。方法采用非负主成分分析法(non-negative principal component analysis,NPCA),基于非负稀疏主成分算法(non-negative sparse principal component analysis,NSPCA)对170名治疗心血管疾病的临床医师的11个临床工作绩效指标进行综合指数拟合。同时,基于根本原因评估技术(root cause assessment techniques)构建置信区间计算每一名临床医师各指标范围。结果门诊出院诊断符合率、手术切口甲级愈合率、手术患者比例、三日确诊率、开展三级和四级手术比例、完成手术及操作数在区分临床医师工作绩效上较为显著,而术前平均住院日、30天内非计划再入院率、出院患者平均住院日、主要诊断治愈/好转、收治患者数在区分临床医师临床工作绩效上不显著。通过综合指数拟合可对所有临床医师的整体工作绩效进行排名,进一步对各具体指标的高、中、低绩效评估可针对性地揭示每一名临床医师潜在的改建维度。结论利用机器学习技术实现以医疗大数据为载体综合评价临床医师临床工作绩效,有望为更科学、客观地评价临床医师工作绩效提供重要支撑。展开更多
文摘In this paper, the generalized variational principle of dynamic analysis for the blast-resistant underground structures is established, and the corresponding generalized functional of elastoplastic analysis for underground structures is derived, and the generalized variational principle of nonconservative system is given, thus the fundamental of dynamical analysis for underground structures to resist blast is proposed. Finally, for the underground cylindrical structure to resist blast, dynamical calculations are made, and compared with the test results.
文摘The structural deformation velocity plays a significant role in the dynamic calculation of underground blast-resistant structures. The motion differentiating equation of a structure system taking into account the role of deformation velocity of the structure will truthfully describe the actual situation of structural vibration. With the one-dimensional plane wave theory, the expression of load on the structural periphery is developed, and the generalized variation principle for the dynamic analysis of underground arched-bar structures is given. At the same time, the results of the numerical calculation are compared.
文摘Shuangchao 25 was derived from the cross ofShuanggui 36/Kang 2 in 1983.The female parentwas a panicle-number type with quick growth andstrong-tiUering ability.The male parent was apanicle-weight type with Bl and BB resistance.The segregated progenies were selected by the"Method of Combination and Population Selec-
基金financial support from National Natural Science Foundation of China(Grant No.11302261 and No.11972201)supported by the project of Key Laboratory of Impact and Safety Engineering(Ningbo University),Ministry of Education.The project number is CJ202011.
文摘In this paper,UR50 ultra-early-strength cement-based self-compacting high-strength concrete slabs(URCS)have been subjected to contact explosion tests with different TNT charge quality,aiming to evaluate the anti-explosive performance of URCS.In the experiment,three kinds of ultra-early-strength cement-based reinforced concrete slabs with different reinforcement ratios and a normal concrete slab(NRCS)were used as the control specimen,the curing time of URCS is 28 days and 24 h respectively.The research results show that URCS has a stronger anti-explosion ability than NRCS.The failure mode of URCS under contact explosion is that the front of the reinforced concrete slab explodes into a crater,and the back is spall.With the increase of the charge,the failure mode of the reinforced concrete slab gradually changed to explosive penetration and explosive punching.The experiment results also show that the reinforcement ratio of URCS has little effect on the anti-blast performance,and URCS can reach its anti-blast performance at 28 days after curing for 24 h.On this basis,the damage parameters of URCS for different curing durations were quantified,and an empirical formula for predicting the diameter of the crater and spalling was established.
文摘目的利用医疗大数据和机器学习技术相结合,探索基于临床结果的临床医师绩效评价方法。方法采用非负主成分分析法(non-negative principal component analysis,NPCA),基于非负稀疏主成分算法(non-negative sparse principal component analysis,NSPCA)对170名治疗心血管疾病的临床医师的11个临床工作绩效指标进行综合指数拟合。同时,基于根本原因评估技术(root cause assessment techniques)构建置信区间计算每一名临床医师各指标范围。结果门诊出院诊断符合率、手术切口甲级愈合率、手术患者比例、三日确诊率、开展三级和四级手术比例、完成手术及操作数在区分临床医师工作绩效上较为显著,而术前平均住院日、30天内非计划再入院率、出院患者平均住院日、主要诊断治愈/好转、收治患者数在区分临床医师临床工作绩效上不显著。通过综合指数拟合可对所有临床医师的整体工作绩效进行排名,进一步对各具体指标的高、中、低绩效评估可针对性地揭示每一名临床医师潜在的改建维度。结论利用机器学习技术实现以医疗大数据为载体综合评价临床医师临床工作绩效,有望为更科学、客观地评价临床医师工作绩效提供重要支撑。
