To investigate the disturbance-induced shear instability mechanism of structural catastrophe in the deep rock mass,MTS 815 material testing machine was used to carry out quasi-static loading tests and disturbance shea...To investigate the disturbance-induced shear instability mechanism of structural catastrophe in the deep rock mass,MTS 815 material testing machine was used to carry out quasi-static loading tests and disturbance shear tests on symmetrical regular dentate joints of two materials at three undulation angles under specific initial static stress,disturbance frequency,and peak value.The test results indicate that:(i)the total ultimate instability displacement is only related to the intrinsic properties of the joints but not to the initial static stress and disturbance parameters;(ii)the cumulative irreversible displacement required for the disturbance instability conforms to the logistic inverse function relationship with the number of disturbances,displaying the variation trend of“rapid increase in the front,stable in the middle,and sudden increase in the rear”;(iii)the accumulation of plastic deformation energy is consistent with the evolution law of irreversible displacement of joints and the overall proportion of hysteretic energy is not large;(iv)the dissipated energy required for the instability of each group of joints is basically the same under various disturbance conditions,and this energy is mainly controlled by the initial shear stress and has no connection with the disturbance parameters.The stability of the total disturbance deformation and the disturbance energy law of the joints revealed in the tests provide data support for reasonably determining the disturbance instability criterion of joints.展开更多
Many mutants of plant induced by heavy ion beam irradiation have been reported in recent years,but leaf anthocyan mutants induced by ion irradiation in evergreen were rarely found.In this study,a color-leaf mutant wit...Many mutants of plant induced by heavy ion beam irradiation have been reported in recent years,but leaf anthocyan mutants induced by ion irradiation in evergreen were rarely found.In this study,a color-leaf mutant with purple leaves,stems and petals was isolated from clones of Wandering Jew irradiated by 95.8 MeV/u carbon ion beam.The concentration and histological distribution of leaf pigment were surveyed in wild type and mutant.In mutant,contents of total chlorophylls (Chl),chlorophyll a (Chl a),chlorophyll b (Chl b) and carotenoids (Car) decreased significantly,while concentration of the anthocyanins was 6.2-fold higher than that of wild type.Further composition analysis of anthocyanins by electrospray ionization mass spectrometry (ESI-MS) indicated that the purple pigmentation of leaves in mutant was caused by accumulation of petunidin anthocyanin.Microscopic examination showed that most petunidin anthocyanin accumulated in the lower epidermis,and little in vascular parenchyma of mutant,while there was no pigment in wild type.Meanwhile,in spongy parenchyma of mutant we observed little Chl,which the wild type abounds in.In conclusion,the color-leaf mutant of Wandering Jew induced by irradiation of carbon ions was improved in ornamental value,and it could be contribute to variation in level,component and distribution of foliar pigment.The possible mutation mechanisms were discussed.展开更多
An important factor of the physical and chemical properties of solution, pH is the index of hydrogen ionconcentration in solution. When the pH is higher or lower than the fitness value, the enzyme activity of bacteria...An important factor of the physical and chemical properties of solution, pH is the index of hydrogen ionconcentration in solution. When the pH is higher or lower than the fitness value, the enzyme activity of bacteriagrowth and metabolism will decrease, and the metabolism of cell will be blocked, which could cause arrest of growthand affect the cell membrane potential, then the biological function of cell membrane would be changed, and also,the material in and out of cell would be influenced. When the pH of fermented liquid is lower in the produceacid fermentation period, the activity of glutamate dehydrogenase will reduce, and the metabolism of substanceand energy will be in the direction of acetyl glutamine synthesis, which could cause the decline of glutamic acidproductivity.展开更多
基金National Natural Science Foundation of China,Grant/Award Numbers:51979280,52279120。
文摘To investigate the disturbance-induced shear instability mechanism of structural catastrophe in the deep rock mass,MTS 815 material testing machine was used to carry out quasi-static loading tests and disturbance shear tests on symmetrical regular dentate joints of two materials at three undulation angles under specific initial static stress,disturbance frequency,and peak value.The test results indicate that:(i)the total ultimate instability displacement is only related to the intrinsic properties of the joints but not to the initial static stress and disturbance parameters;(ii)the cumulative irreversible displacement required for the disturbance instability conforms to the logistic inverse function relationship with the number of disturbances,displaying the variation trend of“rapid increase in the front,stable in the middle,and sudden increase in the rear”;(iii)the accumulation of plastic deformation energy is consistent with the evolution law of irreversible displacement of joints and the overall proportion of hysteretic energy is not large;(iv)the dissipated energy required for the instability of each group of joints is basically the same under various disturbance conditions,and this energy is mainly controlled by the initial shear stress and has no connection with the disturbance parameters.The stability of the total disturbance deformation and the disturbance energy law of the joints revealed in the tests provide data support for reasonably determining the disturbance instability criterion of joints.
基金Supported by the superintendents'foundation of Institute of Modern Physics,Chinese Academy of Sciences(0906020SZO)
文摘Many mutants of plant induced by heavy ion beam irradiation have been reported in recent years,but leaf anthocyan mutants induced by ion irradiation in evergreen were rarely found.In this study,a color-leaf mutant with purple leaves,stems and petals was isolated from clones of Wandering Jew irradiated by 95.8 MeV/u carbon ion beam.The concentration and histological distribution of leaf pigment were surveyed in wild type and mutant.In mutant,contents of total chlorophylls (Chl),chlorophyll a (Chl a),chlorophyll b (Chl b) and carotenoids (Car) decreased significantly,while concentration of the anthocyanins was 6.2-fold higher than that of wild type.Further composition analysis of anthocyanins by electrospray ionization mass spectrometry (ESI-MS) indicated that the purple pigmentation of leaves in mutant was caused by accumulation of petunidin anthocyanin.Microscopic examination showed that most petunidin anthocyanin accumulated in the lower epidermis,and little in vascular parenchyma of mutant,while there was no pigment in wild type.Meanwhile,in spongy parenchyma of mutant we observed little Chl,which the wild type abounds in.In conclusion,the color-leaf mutant of Wandering Jew induced by irradiation of carbon ions was improved in ornamental value,and it could be contribute to variation in level,component and distribution of foliar pigment.The possible mutation mechanisms were discussed.
文摘An important factor of the physical and chemical properties of solution, pH is the index of hydrogen ionconcentration in solution. When the pH is higher or lower than the fitness value, the enzyme activity of bacteriagrowth and metabolism will decrease, and the metabolism of cell will be blocked, which could cause arrest of growthand affect the cell membrane potential, then the biological function of cell membrane would be changed, and also,the material in and out of cell would be influenced. When the pH of fermented liquid is lower in the produceacid fermentation period, the activity of glutamate dehydrogenase will reduce, and the metabolism of substanceand energy will be in the direction of acetyl glutamine synthesis, which could cause the decline of glutamic acidproductivity.
