ABSTRACT
Macroscopic parameters as well as precise information on the random force characterizing the Langevin-type description of the nuclear fusion process around the Coulomb barrier are extracted from the microscopic dynamics of individual nucleons by exploiting the numerical simulation of the improved quantum molecular dynamics. It turns out that the dissipation dynamics of the relative motion between two fusing nuclei is caused by a non-Gaussian distribution of the random force. We find that the friction coefficient as well as the time correlation function of the random force takes particularly large values in a region a little bit inside of the Coulomb barrier. A clear non-Markovian effect is observed in the time correlation function of the random force. It is further shown that an emergent dynamics of the fusion process can be described by the generalized Langevin equation with memory effects by appropriately incorporating the microscopic information of individual nucleons through the random force and its time correlation function.
ABSTRACT
ObjectiveTo analyze the prevalence and epidemic trend of human brucellosis between 2007 -2010 in Qian'an county,and to provide a basis for future prevention and control measures. Methods Epidemiological data of brucellosis between 2007 - 2010 were obtained from the national disease surveillance report on management information system, population data were from the national disease surveillance information management system for basic information reporting system, and descriptive epidemiological methods was used for statistical analysis. Results A total of 86 cases were infected with brucellosis in Qian'an county from 2007 to 2010, with 68 cases of male and 18 cases of female, and male to female ratio was 3.78 : 1. Patients were mainly in the age of 20 - 55, with 40 - ＜ 45 year-old group the highest. All patients were local residents. Most professional were livestock acquisition, processing and aquaculture personnel. The majority of patients lived in Jianchang town,with 51 cases, accounting for 59.30％. Thirteen patients were reported in 2007, incidence was 0.0201‰(13/ 647 983). Thirty-nine patients were reported in 2010, and incidence was 0.0563‰(39/657 380). There was a fluctuations increase from 2007 to 2010. In 2007 brucellosis occurred in only two townships(towns), which spread to eight townships (towns) and urban areas in 2010. ConclusionsThe epidemic of human brucellosis in Qian'an is in a spreading trend. We recommend the government to strengthen the quarantine of livestock, and the infected livestock should be timely treated. Strengthen the prevention and control in Jianchangying. At the same time increase the brucellosis propaganda, and enhance self-protection awareness of the occupational groups.
