In engineering materials such as cast iron and concrete,there is a fracture process zone in the crack front and it exists micro and macro defect and energy dissipation,so its quasi-brittle fracture performance prevail.The damage development area is simplified into virtual crack,and crack cohesive stress distribution and opening displacement or deformation exist among it.In order to explore the constitutive relation of crack opening displacement and stress of cohesive crack in quasi brittle materials,cast iron and concrete were used to test their fracture process and micro view experiment.By the analytical method of applied mathematics mechanics,the material deformation stress constitutive relations were obtained for the crack development zone.And,based on the mechanical model and double K fracture criterion,the estimate calculation of structure bearing capacity with crack was also given in the paper.The theoretical calculation and test results are basically identical./r/n

Some experiments were carried out to probe into the differences of the appearance characters,internal quality,chemical components and physical traits among the flue-cured tobacco leaves at different stalk position.The results could help for tobacco leaf grading according to the leaf appearance characters.

Objective:To investigate the diagnosis value of TTM(thermal texture maps system)between knee osteoarthritis and wind-dampness arthralgia.Methods:Thirty-six cases of osteoarthritis and 56 cases of wind-dampness arthralgia which all had been definitely diagnosed were chosen to have TTM scanning both anterior and posterior.The form and intensity of the heat were compared.Results:Comparisons between heat forms of anterior TTM scanning: the heat forms of wind-dampness arthralgia patients were larger cooler zone with round or oval shape,and that of knee osteoarthritis patients were hot zone with irregular shape;comparisons between heat forms of posterior TTM scanning:the heat forms of both the two kind diseases all appeared as hot zone with small oval shape;comparisons of heat values: the heat values of anterior TTM scanning of knee osteoarthritis group was significantly higher than that in wind-dampness arthralgia group(P<0.01).Heat values of posterior TTM scanning in knee osteoarthritis group and wind-dampness arthralgia group had no significant difference(P>0.05).Conclusion:TTM can be an indicator in the differential diagnosis between knee osteoarthritis and wind-dampness arthralgia.

Splitting rate of composite supermicrofiber is related to the separate splitting rate and gap splitting rate.With evaluation index of splitting rate,weight reduction rate,water absorbency,capillary effect,and fiber loss,the influences of NaOH concentration,temperature,time and mechanical force on splitting effect of PET/PA composite supermicrofiber were discussed.With orthogonal test method,the optimal processing conditions were determined,those are NaOH concentration 5g/L,temperature 110℃ and time 45 min,. The mechanical force effect in splitting process was also studied.The results showed that the mechanical force could be beneficial to the splitting of PET/PA supermicrofiber.