The GIS and analysis of earthquake damage distribution of the 1303 Hongtong M=8 earthquake

The geography information system of the 1303 Hongtong M=8 earthquake has been established. Using the spatial analysis function of GIS, the spatial distribution characteristics of damage and isoseismal of the earthquake are studied. By comparing with the standard earthquake intensity attenuation relationship, the abnormal damage dis-tribution of the earthquake is found, so the relationship of the abnormal distribution with tectonics, site condition and basin are analyzed. In this paper, the influence on the ground motion generated by earthquake source and the underground structures near source also are studied. The influence on seismic zonation, anti-earthquake design, earthquake prediction and earthquake emergency responding produced by the abnormal density distribution are discussed.

Spatial damage distribution of August 16,2003,Inner Mongolia,China,M_S=5.9 earth-quake and analysis

The spatial damage distribution of August 16, 2003, Inner Mongolia, China, MS=5.9 earthquake is summarized through field investigation. The moment tensor solution and focal mechanism are inverted using the digital long-period waveform records of China Digital Seismograph Network (CDSN). The relation between the spatial damage distribution and focal mechanism is analyzed according to the focal mechanism, the aftershock distribution and the spatial damage distribution. The possible relation between the characteristics of ground motion and the tectonic background of the source region is discussed in terms of the global ground motion records, historical earthquake documents and the damage distribution. Investigation reveals that the meizoseismal region is in east-west direction, which is consistent with the nodal plane of focal mechanism inversion. The meizoseismal area is relatively large and the damage of single-story adobe houses or masonry houses is more severe. This may have relations with local seismotectonic environment.

Evaluation and optimization of blasting approaches to reducing oversize boulders and toes in open-pit mine

A new blasting approach of combined blastholes with different diameters is proposed to solve the problems of oversize boulders and rock toes in open-pit mine. A non-ideal detonation model and a statistical damage constitutive model are implemented in dynamic finite element analysis to investigate the formation mechanism of oversize boulders and toes. The damage distribution and evolution process of rock blasting fragmentation is simulated, and the scheme is further optimized. Numerical analysis results showed that pocket charges and satellite blastholes can only improve bench top fragmentation, but they cannot reduce the oversize in the middle and bottom of bench as well as the toe problem. The new blasting approach of combined blastholes with different diameters can effectively reduce the oversize boulders and toes as well as the production costs.

Numerical Simulations of Tungsten Alloy Rods Penetration into Alumina Ceramic/Armor Steel Composite Target

The Johnson-Holmquist constitutive ceramic model is re-implemented into the LS_ DYNA3D program to simulate the penetration of long rod projectile into ceramic/armor steel composite targets. The damage evolution, fracture propagation, and spall damage in the ceramic/armor targets is represented during the simulation procedure and the accuracy of the penetration depth comparing between the simulating and experimental results is reliable with an error less than 8 %. The relationship between the mass efficiency factor, differential factor and ceramic tiles thickness is given out for the penetration results with/without a cover plate.

Effect of standing-wave field distribution on femosecond laser-induced damage of HfO_2/SiO_2 mirror coating

Single-pulse and multi-pulse damage behaviors of ＂standard＂ （with A/4 stack structure） and ＂modified＂ （with reduced standing-wave field） HfO2/SiO2 mirror coatings are investigated using a commercial 50-fs, 800-nm Ti：sapphire laser system. Precise morphologies of damaged sites display strikingly different features when the samples are subjected to various number of incident pulses, which are explained reasonably by the standing-wave field distribution within the coatings. Meanwhile, the single-pulse laser-induced damage threshold of the ＂standard＂ mirror is improved by about 14% while suppressing the normalized electric field intensity at the outmost interface of the HfO2 and SiO2 layers by 37%. To discuss the damage mechanism, a theoretical model based on photoionization, avalanche ionization, and decays of electrons is adopted to simulate the evolution curves of the conduction-band electron densitv during r^ulse dHratian.

Oxidative capacities of size-segregated haze particles in a residential area of Beijing

The frequent haze days around the Chinese capital of Beijing in recent years have aroused great attention owing to the detrimental effects on visibility and public health. To discover the potential health effects of the haze, oxidative capacities of airborne particles collected in Beijing during haze and clear days were comparably assessed by a plasmid scission assay. Eleven water-soluble trace elements （As, Cd, Cr, Cu, Mn, Ni, Pb, V, Se, T1, and Zn） in the size-segregated airborne particles were quantitatively analyzed by inductively coupled plasma mass spectrometry, and most of the water- soluble trace elements were found to mainly concentrate in the fine particle size of 0.56-1.0 μm. In comparison with clear days, the mass concentrations of 11 analyzed water-soluble trace elements remarkably increased during haze days, and the oxidative capacities determined by the plasmid scission assay were markedly elevated accordingly during the haze days under the same dosage of particles as for those during clear days. Water-soluble trace elements in airborne particles, such as Cu, V, and particularly Zn, were found to have significantly positive correlations with the plasmid DNA damage rates. Because Cu, V, and Zn have been considered as bioavailable elements, the evident increase of these elements during haze days may be greatly harmful to human health.