In this paper an experimental study on damage tolerance behaviour of composite panels with softening strips is carried out. A prediction method of residual strength of panels with softening strips is proposed. The com...In this paper an experimental study on damage tolerance behaviour of composite panels with softening strips is carried out. A prediction method of residual strength of panels with softening strips is proposed. The comparison between estimated and experimental results shows that the prediction method can be applied to design. In this paper the failure mechanisms are described.展开更多
This paper deals with the repair of damaged, plain concrete and polymer cement concrete by impregnation with methyl methacrylate (MMA) or sulfur. The stress-strain (σ-ε) curves of the unaxial compression of the conc...This paper deals with the repair of damaged, plain concrete and polymer cement concrete by impregnation with methyl methacrylate (MMA) or sulfur. The stress-strain (σ-ε) curves of the unaxial compression of the concrete before and after repairing were given. The results indicate that the strength of damaged concrete can be reinstated and even improved after the concrete is impregnated with MMA or sulfur. The main mechanism of repairing is that the cracks, the original pores and microcracks are filled with MMA or sulfur, and the im-pregnant plays role in adhesion enhancement and reinforcement.展开更多
Akey national research project on major climate damage has scored important achievements, a spokesman announced at a phased review conference of the project held from October 8 to 13, 2000 in Beijing. Located in the E...Akey national research project on major climate damage has scored important achievements, a spokesman announced at a phased review conference of the project held from October 8 to 13, 2000 in Beijing. Located in the East Asian monsoon area where the interannual variation is great, China suffers a展开更多
Objective: To assess the effect of Xinmaitong (XMT) capsule in treating coronaryheart disease (CHD). Methods: Thirty-eightpatients of coronary heart disease with myocardial ischemia were divided randomly intoXMT group...Objective: To assess the effect of Xinmaitong (XMT) capsule in treating coronaryheart disease (CHD). Methods: Thirty-eightpatients of coronary heart disease with myocardial ischemia were divided randomly intoXMT group (20 cases) and control group (18cases). Conventional western medical therapywas given to both groups and the XMT groupreceived additional XMT treatment. Thechanges of endothelin (ET ) and calcitoningene-related peptide (CGRP) levels, ST segment of ECG and clinical symptoms aftertreatment in all the patients were observed.Data of 14 healthy persons were taken as normal control. Results: The ET level of all patients was significantly higher than that of thenormal control (P < 0. 001 ), and level ofCGRP in patients was not different from normal control significantly (P > 0. 05 ). Aftertreatment, results showed that: (1 ) The ETlevels and the scores of clinical symptoms ofboth groups decreased significantly (P <0. 01 ), and ST segment elevated markedly(P< 0. 01) as compared with before treatment, and the changes revealed more evidentin XMT group in comparison with those of thecontrol group (P < 0.05 - 0.01 ). (2 ) Thelevel of CGRP was significantly increased inXMT group (P < 0. 01 ) while unchanged inthe control group (P > 0. 05 ). Conclusions:There is severe damage of vascular endothelialcells in CHD patients. XMT could not only reduce significantly the plasma ET content, butalso enhance markedly the production and release of CGRP, so it has a good anti--ischemiceffect, which may be closely related with itsaction on improving the function of vascularendothelial cells and regulating metabolism ofET and CGRP.展开更多
Damage zones of brittle-ductile (B-D) transition in PP/EPDM blends are studied in this paper. The contribution of crazing and shear yielding zones in damage zones to energy dissipation of blends was measured with comp...Damage zones of brittle-ductile (B-D) transition in PP/EPDM blends are studied in this paper. The contribution of crazing and shear yielding zones in damage zones to energy dissipation of blends was measured with computer image analysis (CIA) and the transition of shear yielding zone (A_(sh)) with rubber volume fraction (V_f) was also manipulated. Results showed that the B-D transition of impact strength of blends corresponded to the fracture mechanism in PP/EPDM blends, from matrix crazing to matrix shear yielding. In addition, two new parameters, density of energy dissipation for crazing zone (F_(cz)) and for shear yielding zone (F_(sh)), are first obtained in this paper. The value of F_(sh) is about four times larger than that of F_(cz) for PP/EPDM blends, which confirmed that the matrix shear yielding is a more effective way of energy dissipation in blends.展开更多
文摘In this paper an experimental study on damage tolerance behaviour of composite panels with softening strips is carried out. A prediction method of residual strength of panels with softening strips is proposed. The comparison between estimated and experimental results shows that the prediction method can be applied to design. In this paper the failure mechanisms are described.
文摘This paper deals with the repair of damaged, plain concrete and polymer cement concrete by impregnation with methyl methacrylate (MMA) or sulfur. The stress-strain (σ-ε) curves of the unaxial compression of the concrete before and after repairing were given. The results indicate that the strength of damaged concrete can be reinstated and even improved after the concrete is impregnated with MMA or sulfur. The main mechanism of repairing is that the cracks, the original pores and microcracks are filled with MMA or sulfur, and the im-pregnant plays role in adhesion enhancement and reinforcement.
文摘Akey national research project on major climate damage has scored important achievements, a spokesman announced at a phased review conference of the project held from October 8 to 13, 2000 in Beijing. Located in the East Asian monsoon area where the interannual variation is great, China suffers a
文摘Objective: To assess the effect of Xinmaitong (XMT) capsule in treating coronaryheart disease (CHD). Methods: Thirty-eightpatients of coronary heart disease with myocardial ischemia were divided randomly intoXMT group (20 cases) and control group (18cases). Conventional western medical therapywas given to both groups and the XMT groupreceived additional XMT treatment. Thechanges of endothelin (ET ) and calcitoningene-related peptide (CGRP) levels, ST segment of ECG and clinical symptoms aftertreatment in all the patients were observed.Data of 14 healthy persons were taken as normal control. Results: The ET level of all patients was significantly higher than that of thenormal control (P < 0. 001 ), and level ofCGRP in patients was not different from normal control significantly (P > 0. 05 ). Aftertreatment, results showed that: (1 ) The ETlevels and the scores of clinical symptoms ofboth groups decreased significantly (P <0. 01 ), and ST segment elevated markedly(P< 0. 01) as compared with before treatment, and the changes revealed more evidentin XMT group in comparison with those of thecontrol group (P < 0.05 - 0.01 ). (2 ) Thelevel of CGRP was significantly increased inXMT group (P < 0. 01 ) while unchanged inthe control group (P > 0. 05 ). Conclusions:There is severe damage of vascular endothelialcells in CHD patients. XMT could not only reduce significantly the plasma ET content, butalso enhance markedly the production and release of CGRP, so it has a good anti--ischemiceffect, which may be closely related with itsaction on improving the function of vascularendothelial cells and regulating metabolism ofET and CGRP.
基金Project supported by the National Natural Science Foundation of China.
文摘Damage zones of brittle-ductile (B-D) transition in PP/EPDM blends are studied in this paper. The contribution of crazing and shear yielding zones in damage zones to energy dissipation of blends was measured with computer image analysis (CIA) and the transition of shear yielding zone (A_(sh)) with rubber volume fraction (V_f) was also manipulated. Results showed that the B-D transition of impact strength of blends corresponded to the fracture mechanism in PP/EPDM blends, from matrix crazing to matrix shear yielding. In addition, two new parameters, density of energy dissipation for crazing zone (F_(cz)) and for shear yielding zone (F_(sh)), are first obtained in this paper. The value of F_(sh) is about four times larger than that of F_(cz) for PP/EPDM blends, which confirmed that the matrix shear yielding is a more effective way of energy dissipation in blends.
