Yang Xiang Zhang

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A mixed-phase chemistry box model is applied to study heterogeneous chemistry and its effect on tropospheric gas-phase chemistry, particularly on photochemical production of O 3 and photochemical indicators for O 3-NO x-hydrocarbon sensitivity, under a variety of atmospheric conditions ranging from remote marine to heavily-polluted atmospheres. A subsequent(More)
[1] In this study, we analyzed the seismic phases S, SKS, and SKKS from 31 deep-focus earthquakes in the Tonga-Fiji region recorded in North America between epicentral distances of 85 and 120. The differential traveltimes and amplitude ratios for these phases reveal clear epicentral distance trends not predicted by standard one-dimensional (1-D) reference(More)
[1] Between 105– 115° degrees, the SKS waveform is complicated by the formation of SP d KS, a wave that has segments of P diffraction along the core mantle boundary. While previous studies have primarily focused on the move-out of SP d KS from SKS, we analyze the concomitant reduction of the SKS amplitude. Long-period SKKS/SKS amplitude ratios present a(More)
A long-standing but fundamental question in lightning studies concerns how lightning is initiated inside storms, given the absence of physical conductors. The issue has revolved around the question of whether the discharges are initiated solely by conventional dielectric breakdown or involve relativistic runaway electron processes. Here we report(More)
SUMMARY Surface topography and the weathered zone (i.e., heterogene-ity near the earth's surface) have great effects on elastic wave propagation. Both surface waves and body waves are contaminated by scattering and conversion by the irregular surface to-pographic features. In this paper, we present a 2D numerical solver for the elastic wave equation that(More)
In this paper, we first examine the relationship between the relative particle motions of fluids and solids and the seismic signal received when compressional waves propagate through saturated porous materials. We use a rotated-staggered-grid finite difference modeling scheme to simulate elastic wave phenomena in a digitized 2D structural model obtained(More)
In fractured reservoir development, azimuthal AVO (AVOaz) properties of reflected PP waves from reservoir tops are often used to infer fracture properties. The fracture parameter inversion is based on either an effective media model (EMM) or a discrete fracture model (DFM). We address the differences in fracture properties that may be inferred by AVOaz(More)
BACKGROUND Psychological disorders are common in diabetes mellitus (DM) patients, and the aim of this study was to estimate the prevalence of psychological distress and to determine the influence factors associated with psychological distress among DM patients in the Jilin province of China. METHODS AND MATERIALS Multistage, stratified cluster sampling(More)
Aerosol particles can affect cloud microphysical properties by serving as ice nuclei (IN). Large uncertainties exist in the ice nucleation parameterizations (INPs) used in current climate models. In this Part II paper, to examine the sensitivity of the model predictions to different heterogeneous INPs, WRF-CAM5 simulation using the INP of Niemand et al.(More)
Introduction Air pollution models have provided the most effective means to quantify the impact of human activities on the atmosphere and to develop balanced and cost-effective emission control strategies for toxic air pollutants such as tropospheric O 3 during the last several decades. The effectiveness of these abatement strategies depends on the(More)