Alfvn Waves in the Solar Wind

Alfvn waves are found to be ubiquitous in the solar wind.Recent progress in observational studies of the waves is reviewed to formulate a microscopic picture for the Alfvenic fluctuations. The main aspects of the observational properties of these waves,including the wave intervals, propagation,evolution,origin and generation,are presented.Then Alfven wave heating and acceleration of the solar wind plasma are briefly introduced.The relation of the waves to rotational and tangential discontinuities,magnetic decreases,and other relatively large-scale structures such as flux tubes/ropes,magnetic clouds and interplanetary coronal mass ejections in the solar wind is particularly investigated.Finally,some remaining open questions are also indicated due to their fundamental importance of understanding of the physical nature of Alfven waves and the role of the waves in heating and accelerating the solar wind.

Risk Evaluation Based on Variable Fuzzy Sets and Information Diffusion Method

Risk evaluation is an effective way to reduce the impacts of natural hazards and it plays an increasingly important role in emergency management. Traditional methods of assessing risks mainly utilize Geographic Information System (GIS) to get risk map, and information diffusion method (IDM) to deal with incomplete data sets. However, there are few papers discuss the uncertainty of integrated hazards and consider dynamic risk under time dimension. The model proposed in this study combines the variable fuzzy set theory with information diffusion method (VFS-IDM) to solve the uncertainness of multiple hazards dynamic risk assessment when data sets are incomplete. This study employs fuzzy set theory (VFS) to calculate the relative membership degree and applies information entropy method (IEM) to obtain the weights of criteria indicators for multiple hazards evaluation. Then applies information diffusion method (IDM) to estimate condition probability distribution and vulnerability curve with the VFS-IEM model results, time data and multiple hazards losses. Then the expected value of multiple hazards dynamic risk can be calculated by using the normal information diffusion estimator so as to improve the accuracy of risk evaluation results.

Measurement of the integrated Luminosities of cross-section scan data samples around theψ(3770)mass region

To investigate the nature of the Ψ（3770） resonance and to measure the cross section for e^＋e^-→DD, a cross-section scan data sample, distributed among 41 center-of-mass energy points from 3.73 to 3.89 GeV, was taken with the BESIII detector operated at the BEPCII collider in the year 2010. By analyzing the large angle Bhabha scattering events, we measure the integrated luminosity of the data sample at each center-of-mass energy point. The total integrated luminosity of the data sample is 76.16±0.04±0.61 pb^-1, where the first uncertainty is statistical and the second systematic.