The jacket structure has become more popular as the offshore wind-turbine support structure. K-type and inverted-K-type jacket support structures have superior potential due to their fewer joints and lower cost of man...The jacket structure has become more popular as the offshore wind-turbine support structure. K-type and inverted-K-type jacket support structures have superior potential due to their fewer joints and lower cost of manufacture and installation. A numerical study was presented on the dynamic responses of K-type and inverted-K-type jacket support structures subjected to different kinds of dynamic load. The results show that the inverted-K-type jacket structure has higher natural frequencies than the K-type. The wave force spectrum response shows that the maximum displacement of the K-type jacket structure is larger than that of the inverted-K-type. The time-history responses under wind and wave-current load indicate that the inverted-K-type jacket structure shows smaller displacement and stress compared with the K-type, and presents different stress concentration phenomena. The dynamic responses reveal that the inverted-K-type of jacket support structure has greater stiffness and superior mechanical properties, and thus is more applicable in the offshore area with relatively deep water.展开更多
Excessive displacement responses of monopiles affect the serviceability of offshore structures.Related to complicated pile−seabed−wave interactions,the actual behavior of monopiles in silty seabed under periodic wave ...Excessive displacement responses of monopiles affect the serviceability of offshore structures.Related to complicated pile−seabed−wave interactions,the actual behavior of monopiles in silty seabed under periodic wave action remains unclear,and relevant studies in the literature are limited.A series of experiments were conducted in a wave flume containing single piles in silty seabed with relative density of 0.77 subjected to regular waves.Two stages of wave loading were applied successively,accompanied by data recording which included pore water pressure,water surface elevation,pile head displacement,and pile strain.Development of pile-head displacement and pore pressure in silty seabed was the main focus,but the effects of pile diameter,pile type,and pile stiffness were also investigated.The experimental results indicate that,in silty seabed,piles of large diameter or with fins accelerate soil liquefaction,resulting in strengthened soil which allows a higher upper boundary of pore pressure.Using fins at deeper locations led to a quick failure of the piles,but the opposite result was observed with an increase in fin dimensions.Once pile-head displacement entered its rapid development period,the wave load calculated via the pile moment was an overestimation,especially for the piles of large diameter.展开更多
Objective: To evaluate the clinical efficacy of aligned acupuncture at the muscle regions plus cutaneous needle for post-stroke upper limb spasticity.Methods: By adopting a design of multicenter randomized controlled ...Objective: To evaluate the clinical efficacy of aligned acupuncture at the muscle regions plus cutaneous needle for post-stroke upper limb spasticity.Methods: By adopting a design of multicenter randomized controlled clinical trial, 488 patients with post-stroke upper limb spasticity were randomized into a treatment group and a control group, 244 in each group. In addition to rehabilitation training, the treatment group received aligned acupuncture at the muscle regions plus cutaneous needle therapy and the control group received conventional Western medicine. After successive 3-week treatments, the clinical efficacy, spasticity degree of the upper limb, joint function, and neurological defect degree were evaluated in the two groups. Results: The total effective rate was 93.4% in the treatment group versus 61.5% in the control group, and the difference was statistically significant(P < 0.05). The upper-limb spasticity degree, joint function, and neurological defect degree were improved significantly in both groups after intervention(P<0.05), and the improvements in the treatment group were more significant than those in the control group(P<0.05 or P<0.01). Conclusion: Aligned acupuncture at the muscle regions plus cutaneous needle therapy is effective in treating post-stroke upper limb spasticity.展开更多
基金Project(51509081)supported by the National Natural Science Foundation of ChinaProject(B12032)supported by the “111 Project” of ChinaProjects(BK20150037,BK20150811)supported by the Natural Science Foundation of Jiangsu Province,China
文摘The jacket structure has become more popular as the offshore wind-turbine support structure. K-type and inverted-K-type jacket support structures have superior potential due to their fewer joints and lower cost of manufacture and installation. A numerical study was presented on the dynamic responses of K-type and inverted-K-type jacket support structures subjected to different kinds of dynamic load. The results show that the inverted-K-type jacket structure has higher natural frequencies than the K-type. The wave force spectrum response shows that the maximum displacement of the K-type jacket structure is larger than that of the inverted-K-type. The time-history responses under wind and wave-current load indicate that the inverted-K-type jacket structure shows smaller displacement and stress compared with the K-type, and presents different stress concentration phenomena. The dynamic responses reveal that the inverted-K-type of jacket support structure has greater stiffness and superior mechanical properties, and thus is more applicable in the offshore area with relatively deep water.
基金financially supported by the Fundamental Research Funds for the Central Universities (B200202050)China Communications Construction Company (2018-ZJKJ-01)National Natural Science Foundation of China (No.51408185)
文摘Excessive displacement responses of monopiles affect the serviceability of offshore structures.Related to complicated pile−seabed−wave interactions,the actual behavior of monopiles in silty seabed under periodic wave action remains unclear,and relevant studies in the literature are limited.A series of experiments were conducted in a wave flume containing single piles in silty seabed with relative density of 0.77 subjected to regular waves.Two stages of wave loading were applied successively,accompanied by data recording which included pore water pressure,water surface elevation,pile head displacement,and pile strain.Development of pile-head displacement and pore pressure in silty seabed was the main focus,but the effects of pile diameter,pile type,and pile stiffness were also investigated.The experimental results indicate that,in silty seabed,piles of large diameter or with fins accelerate soil liquefaction,resulting in strengthened soil which allows a higher upper boundary of pore pressure.Using fins at deeper locations led to a quick failure of the piles,but the opposite result was observed with an increase in fin dimensions.Once pile-head displacement entered its rapid development period,the wave load calculated via the pile moment was an overestimation,especially for the piles of large diameter.
基金supported by Scientific Research Project of Hebei Provincial Administration Bureau of Traditional Chinese Medicine (No. 2009180)
文摘Objective: To evaluate the clinical efficacy of aligned acupuncture at the muscle regions plus cutaneous needle for post-stroke upper limb spasticity.Methods: By adopting a design of multicenter randomized controlled clinical trial, 488 patients with post-stroke upper limb spasticity were randomized into a treatment group and a control group, 244 in each group. In addition to rehabilitation training, the treatment group received aligned acupuncture at the muscle regions plus cutaneous needle therapy and the control group received conventional Western medicine. After successive 3-week treatments, the clinical efficacy, spasticity degree of the upper limb, joint function, and neurological defect degree were evaluated in the two groups. Results: The total effective rate was 93.4% in the treatment group versus 61.5% in the control group, and the difference was statistically significant(P < 0.05). The upper-limb spasticity degree, joint function, and neurological defect degree were improved significantly in both groups after intervention(P<0.05), and the improvements in the treatment group were more significant than those in the control group(P<0.05 or P<0.01). Conclusion: Aligned acupuncture at the muscle regions plus cutaneous needle therapy is effective in treating post-stroke upper limb spasticity.