The eukaryotic genome is organized within cells as chromatin,which is constantly threatened by genotoxic factors including ionizing radiation,and then resulting in the formation of various DNA lesions.
The constant m_(i) in the Hoek-Brown(H-B) criterion is a fundamental parameter required for determining the compressive strength of rock. In this paper, drilling parameters provide a new basis for determining the cons...The constant m_(i) in the Hoek-Brown(H-B) criterion is a fundamental parameter required for determining the compressive strength of rock. In this paper, drilling parameters provide a new basis for determining the constant mi. An analytical relationship between the drilling parameters and constant miis established in consideration of the contact response between the drilling bit and the cut rock in the crushed zone.New models are developed to predict the triaxial compressive strength(TCS), internal friction angle φand cohesion c of rock. Drilling tests are carried out on 6 rock types to study the correlation between φ and m_(i). A comparison between the predicted values of rock mechanical properties and the measured values from the laboratory is performed to verify the accuracy of the proposed model(yielding an error less than 10%). The TCSs and constant m_(i) values of fifteen rocks are cited to validate the accuracy of the proposed model. The result shows that the proposed model predicts the TCS and constant m_(i) within a maximum error of 20%. The method can be conveniently applied to the rock mechanical properties.展开更多
In this article we extend the notion of constant angle surfaces in S2 × R and H2 ×R to general Bianchi-Cartan-Vranceanu spaces. We show that these surfaces have constant Gaussian curvature and we give a comp...In this article we extend the notion of constant angle surfaces in S2 × R and H2 ×R to general Bianchi-Cartan-Vranceanu spaces. We show that these surfaces have constant Gaussian curvature and we give a complete local classification in the Heisenberg group.展开更多
The variations in the viscoelastic characteristics of asphalt concrete due to testing mode are assessed and modeled in the present investigation.Asphalt concrete mixture was prepared at its optimum asphalt binder requ...The variations in the viscoelastic characteristics of asphalt concrete due to testing mode are assessed and modeled in the present investigation.Asphalt concrete mixture was prepared at its optimum asphalt binder requirement and compacted in slab mold with the aid of roller compaction.Beam specimens of 6.2 cm width,5.6 cm depth,and 40 cm length,were obtained from the slab samples with the aid of a diamond saw,and tested using controlled stress and strain techniques under dynamic flexural stresses.The viscoelastic properties such as the phase angle,cumulative dissipated energy,permanent deformation,flexural stiffness,and micro strain were monitored and modeled among the two testing techniques.It was noticed that higher micro strain and permanent deformation are detected when testing the asphalt concrete specimens under constant strain mode.However,higher phase angle,flexural stiffness,and energy dissipation could be observed under the constant stress mode of the test.展开更多
文摘The eukaryotic genome is organized within cells as chromatin,which is constantly threatened by genotoxic factors including ionizing radiation,and then resulting in the formation of various DNA lesions.
基金sponsored by the National Natural Science Foundation of China (Nos. 42177158, 11902249 and 11872301)Natural Science Foundation of Shaanxi Province (Shaanxi Province Natural Science Foundation) (No. 2019JQ395)Education Bureau of Shaanxi Province | Scientific Research Plan Projects of Shaanxi Education Department in China (No. 20JS093)。
文摘The constant m_(i) in the Hoek-Brown(H-B) criterion is a fundamental parameter required for determining the compressive strength of rock. In this paper, drilling parameters provide a new basis for determining the constant mi. An analytical relationship between the drilling parameters and constant miis established in consideration of the contact response between the drilling bit and the cut rock in the crushed zone.New models are developed to predict the triaxial compressive strength(TCS), internal friction angle φand cohesion c of rock. Drilling tests are carried out on 6 rock types to study the correlation between φ and m_(i). A comparison between the predicted values of rock mechanical properties and the measured values from the laboratory is performed to verify the accuracy of the proposed model(yielding an error less than 10%). The TCSs and constant m_(i) values of fifteen rocks are cited to validate the accuracy of the proposed model. The result shows that the proposed model predicts the TCS and constant m_(i) within a maximum error of 20%. The method can be conveniently applied to the rock mechanical properties.
文摘In this article we extend the notion of constant angle surfaces in S2 × R and H2 ×R to general Bianchi-Cartan-Vranceanu spaces. We show that these surfaces have constant Gaussian curvature and we give a complete local classification in the Heisenberg group.
文摘The variations in the viscoelastic characteristics of asphalt concrete due to testing mode are assessed and modeled in the present investigation.Asphalt concrete mixture was prepared at its optimum asphalt binder requirement and compacted in slab mold with the aid of roller compaction.Beam specimens of 6.2 cm width,5.6 cm depth,and 40 cm length,were obtained from the slab samples with the aid of a diamond saw,and tested using controlled stress and strain techniques under dynamic flexural stresses.The viscoelastic properties such as the phase angle,cumulative dissipated energy,permanent deformation,flexural stiffness,and micro strain were monitored and modeled among the two testing techniques.It was noticed that higher micro strain and permanent deformation are detected when testing the asphalt concrete specimens under constant strain mode.However,higher phase angle,flexural stiffness,and energy dissipation could be observed under the constant stress mode of the test.
