Imbalance and Polarization of Spatial Distribution of China's Swine Production

Based on annual pork yield of each province in 1996-2014,using Gini coefficient and spatial polarization index model,empirical analysis was carried out for spatial imbalance and polarization degree of swine production distribution. Results indicate that there is high imbalance in spatial distribution of swine production. The imbalance takes on first rise then declines with fluctuation,largely because of inter-group gap. From the perspective of regions,the regions with balanced grain production have the highest imbalance in swine production,followed by main sales regions,and the main grain production regions have the lowest imbalance. The polarization index indicates that the overall polarization degree of the spatial distribution of swine production takes on a growing trend,and that of each functional region of grain production is also growing.

Using the physical decomposition method to study the effects of Arctic factors on wintertime temperatures in the Northern Hemisphere and China

The physical decomposition method separates atmospheric variables into four parts, correlating each with solar radiation, land-sea distribution, and inter-annual and seasonal internal forcing, strengthening the anomaly signal and increasing the correlation between variables. This method was applied to the reanalysis data from the National Centers for Environmental Prediction/National Center for Atmospheric Research （NCEP/NCAR）, to study the effects of Arctic factors （Arctic oscillation （AO） and Arctic polar vortex） on wintertime temperatures in the Northern Hemisphere and China. It was fotmd that AO effects on zonal average temperature disturbance could persist for 1 month. In the AO negative phase in wintertime, the temperatures are lower in the mid-high latitudes than in normal years, but higher in low latitudes. When the polar vortex area is bigger, the zonal average temperature is lower at 50N. Influenced mainly by meridional circulation enhancement, cold air flows from high to low latitudes; thus, the temperatures in Continental Europe and the North American continent exhibit an antiphase seesaw relationship. When the AO is in negative phase and the Arctic polar vortex larger, the temperature is lower in Siberia, but higher in Greenland and the Bering Strait. Influenced by westerly troughs and ridges, the polar air disperses mainly along the tracks of atmospheric activity centers. The AO index can be considered a predictor of wintertime temperature in China. When the AO is in negative phase or the Asian polar vortex is intensified, temperatures in Northeast China and Inner Mongolia are lower, because under the influence of the Siberia High and northeast cold vortex, the cold air flows southwards.

Refractive index measurement of dielectric samples using highly focused radially polarized light(Invited Paper)

In this Letter, a refractive index measurement of a dielectric sample using highly focused radially polarized light is reported. Through imaging analysis of the optical field at the pupil plane of a high numerical aperture （NA） objective lens reflected by the sample under study, the Brewster angle is found. Employing a high NA objective lens allows the measurement of multiple angles of incidence from 0° to 64° in a single shot. The refractive index of the sample is estimated using the measured Brewster angle. The experimental results are compared with the theoretical images computed with the Fresnel theory, and a good agreement is obtained.

树轮记录的华北地区过去三个世纪的干旱变化

Droughts are the most frequent natural disaster in regions at the margins of the East Asian summer monsoon(EASM),which pose threats to agriculture,the economy,and human lives.However,the limitations of only approximately 60 years of meteorological observations hamper our understanding of the characteristics and mechanisms of local hydroclimate.Trees growing in the marginal region of the EASM are usually sensitive to moisture variations and have played important roles in past hydroclimatic reconstructions.Here,a 303-year tree-ring-width chronology of Pinus tabulaeformis from Mt.Lama,which is located in the junction of the Liaoning Province and Inner Mongolia,China,was used to reconstruct the May-August Palmer drought severity index(PDSI)in the marginal region of the EASM.The transfer function explains 48.0%(or 47.2%after adjusting for the loss of the degrees of freedom)of the variance over the calibration period from 1946 to 2012.A spatial correlation analysis demonstrates that our PDSI reconstruction can represent the drought variability on the northernmost margin of the EASM.The winter Asian polar vortex area index showed a delayed impact on the summer EASM precipitation in the following year.