A numerical wave tank is used to investigate the onset and strength of unforced wave breaking, and the waves have three types of initial spectra： constant amplitude spectrum, constant steepness spectrum and Pierson-M...A numerical wave tank is used to investigate the onset and strength of unforced wave breaking, and the waves have three types of initial spectra： constant amplitude spectrum, constant steepness spectrum and Pierson-Moscowitz spectrum. Numerical tests are performed to validate the model results. Then, the onset of wave breaking is discussed with geometric, kinematic, and dynamic breaking criteria. The strength of wave breaking, which is always characterized by the fractional energy loss and breaking strength coefficient, is studied for different spectra. The results show how the energy growth rate is better than the initial wave steepness on estimating the fractional energy losses as well as breaking strength coefficient.展开更多
The tensile properties of geotextile are analyzed with the boundary element method, with special emphasis put on the influence of specimen width on geotextile breaking strength. The theoretical and experimental result...The tensile properties of geotextile are analyzed with the boundary element method, with special emphasis put on the influence of specimen width on geotextile breaking strength. The theoretical and experimental results showed that narrow specimen would underestimate the tensile strength of the geotextile. During testing procedure, the lateral contraction of the specimen is the main reason that causes the breaking strength to be on the lower side. The theoretical results also indicate that the breaking strength of the geotextile would arrive at a fixed value when the specimen width is increased to a certain extent.展开更多
The phenolic resin-chloroprene nthher was used for sandwich in manufueturing the vibra-tion damping laminated steel sheet (also calied laminated sheet), Il is a metal matrix com-posite. The tensie-shear tests have bee...The phenolic resin-chloroprene nthher was used for sandwich in manufueturing the vibra-tion damping laminated steel sheet (also calied laminated sheet), Il is a metal matrix com-posite. The tensie-shear tests have been conducted over a range of temperatures from 20C to 150C and at the strain rates from 1.67× 10 ^(5) to 1.67× 10^(-2)s^(-1). The results show that test temperature will significaiilly affect the tensile shear strength of laminated sheet. and a minimal strength and a minimal activation energy occur near 80C . The tensile-shear breaking morphology of laminated sheet varies with strain rate and test temjteralurc.展开更多
Starting from the perspective of formula and efficacy,orthogonal experiments were first performed to explore the optimal ratio of three raw materials that potentially affect breaking force of lipsticks,verification ex...Starting from the perspective of formula and efficacy,orthogonal experiments were first performed to explore the optimal ratio of three raw materials that potentially affect breaking force of lipsticks,verification experiment on humans was then conducted to test the efficacy of the lipstick formula.Results showed that when the ratio of carnauba wax,shea butter and myristyl isopropyl ester was 3∶7∶3,the breaking force was optimal.After the subjects used the lipstick formula for 14 days,the moisture content of the lip stratum corneum significantly increased by 23.51% (P﹤0.05),the transepidermal water loss (TEWL) rate significantly decreased by 20.61%,the skin glossiness increased significantly by 9.88%,and the skin scale index decreased significantly by 55.76%.展开更多
In this paper, the knot strengths of the seven strands which were made of polyethleneterephthalate(PET), nylon 6, polyvinyl formal fibre, polypropylene and polyethylene with differentspecification used for industrial ...In this paper, the knot strengths of the seven strands which were made of polyethleneterephthalate(PET), nylon 6, polyvinyl formal fibre, polypropylene and polyethylene with differentspecification used for industrial purposes were tested and discussed. The results of experimentshow: the knot strength loss does not only depend on the breaking elongation and the diameter ofsample, but also on the shape of the load-extension curve and twist factor of sample and other fac-tors; the range of the knot strength loss and the breaking energy loss vary in a wide range, in thepresent case. the former is from 2.7% to 58.14% and the latter from 16.36% to 78.76%. Thestrength loss of the polypropylene filament is the least among the samples investigated.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.41106019 and 41176016)the Public Science and Technology Research Funds Projects of Ocean(Grant No.201105018)the Scientific Research Fund of the Second Institute of Oceanography,SOA(Grant No.JT1205)
文摘A numerical wave tank is used to investigate the onset and strength of unforced wave breaking, and the waves have three types of initial spectra： constant amplitude spectrum, constant steepness spectrum and Pierson-Moscowitz spectrum. Numerical tests are performed to validate the model results. Then, the onset of wave breaking is discussed with geometric, kinematic, and dynamic breaking criteria. The strength of wave breaking, which is always characterized by the fractional energy loss and breaking strength coefficient, is studied for different spectra. The results show how the energy growth rate is better than the initial wave steepness on estimating the fractional energy losses as well as breaking strength coefficient.
文摘The tensile properties of geotextile are analyzed with the boundary element method, with special emphasis put on the influence of specimen width on geotextile breaking strength. The theoretical and experimental results showed that narrow specimen would underestimate the tensile strength of the geotextile. During testing procedure, the lateral contraction of the specimen is the main reason that causes the breaking strength to be on the lower side. The theoretical results also indicate that the breaking strength of the geotextile would arrive at a fixed value when the specimen width is increased to a certain extent.
文摘The phenolic resin-chloroprene nthher was used for sandwich in manufueturing the vibra-tion damping laminated steel sheet (also calied laminated sheet), Il is a metal matrix com-posite. The tensie-shear tests have been conducted over a range of temperatures from 20C to 150C and at the strain rates from 1.67× 10 ^(5) to 1.67× 10^(-2)s^(-1). The results show that test temperature will significaiilly affect the tensile shear strength of laminated sheet. and a minimal strength and a minimal activation energy occur near 80C . The tensile-shear breaking morphology of laminated sheet varies with strain rate and test temjteralurc.
文摘Starting from the perspective of formula and efficacy,orthogonal experiments were first performed to explore the optimal ratio of three raw materials that potentially affect breaking force of lipsticks,verification experiment on humans was then conducted to test the efficacy of the lipstick formula.Results showed that when the ratio of carnauba wax,shea butter and myristyl isopropyl ester was 3∶7∶3,the breaking force was optimal.After the subjects used the lipstick formula for 14 days,the moisture content of the lip stratum corneum significantly increased by 23.51% (P﹤0.05),the transepidermal water loss (TEWL) rate significantly decreased by 20.61%,the skin glossiness increased significantly by 9.88%,and the skin scale index decreased significantly by 55.76%.
文摘In this paper, the knot strengths of the seven strands which were made of polyethleneterephthalate(PET), nylon 6, polyvinyl formal fibre, polypropylene and polyethylene with differentspecification used for industrial purposes were tested and discussed. The results of experimentshow: the knot strength loss does not only depend on the breaking elongation and the diameter ofsample, but also on the shape of the load-extension curve and twist factor of sample and other fac-tors; the range of the knot strength loss and the breaking energy loss vary in a wide range, in thepresent case. the former is from 2.7% to 58.14% and the latter from 16.36% to 78.76%. Thestrength loss of the polypropylene filament is the least among the samples investigated.
