IDM模型分析及其影响力改进算法

影响力传播模型IDM用于挖掘和分析BBS上观点领袖以及热门话题,它主要以影响力作为衡量标准。通过简化影响力运算法则,对IDM模型进行改进,使其更加直观。此改进后的IDM模型可运用到社会网络中,能更深刻的揭示出社会网络中各通信个体间的相互影响和距离,从而更好地了解和研究社会网络。     

Identification and characterization of the Vibrio anguillarum prtV gene encoding a new metalloprotease

We cloned and sequenced a prtV-like gene from Vibrio anguillarum M3 strain. This prtV gene encodes a putative protein of 918 amino acids, and is highly homologous to the V. cholerae prtV gene. We found that a prtV insertion mutant strain displayed lower gelatinase activity on gelatin agar, lower protease activity against azocasein, and lower activity for four glycosidases. This prtV mutant strain also had increased activity for two esterases in its extracellular products, as analyzed by the API ZYM system. In addition, the prtV mutant strain exhibited decreased growth in turbot intestinal mucus and reduced hemolytic activity on turbot erythrocytes. Infection experiments showed that the LD₅₀ of the prtV mutant strain increased by at least 1 log compared to the wild-type in turbot fish. We propose that prtV plays an important role in the pathogenesis of V. anguillarum.     

Numerical study on inter-tidal transports in coastal seas

Inter-tidal(subtidal) transport processes in coastal sea depend on the residual motion, turbulent dispersion and relevant sources/sinks. In Feng et al.(2008), an updated Lagrangian inter-tidal transport equation, as well as new concept of Lagrangian in- ter-tidal concentration(LIC), has been proposed for a general nonlinear shallow water system. In the present study, the LIC is nu- merically applied for the first time to passive tracers in idealized settings and salinity in the Bohai Sea, China. Circulation and tracer motion in the three idealized model seas with different topography or coastline, termed as ‘flat-bottom', ‘stairs' and ‘cape' case, re- spectively, are simulated. The dependence of the LIC on initial tidal phase suggests that the nonlinearities in the stairs and cape cases are stronger than that in the flat-bottom case. Therefore, the ‘flat-bottom' case still meets the convectively weakly nonlinear condi- tion. For the Bohai Sea, the simulation results show that most parts of it still meet the weakly nonlinear condition. However, the de- pendence of the LIS(Lagrangian inter-tidal salinity) on initial tidal phase is significant around the southern headland of the Liaodong Peninsula and near the mouth of the Yellow River. The nonlinearity in the former region is mainly related to the complicated coast- lines, and that in the latter region is due to the presence of the estuarine salinity front.     

积极探索建立适应社会主义市场经济的地质矿产资源管理新体制

文章从适应社会主义市场经济要求出发,根据我国建立社会主义市场经济体制的理论和成功经验,论述了矿产资源管理方式转变的总体思路、要求、矿产资源管理新体制的构架和运行机制,论述了地方地矿行政管理的职能。     

714C气象雷达电磁干扰的分析及解决方法

雷达设备电磁干扰的解决方法,依赖于对干扰的准确分析。通过昆明机场７１４Ｃ气象雷达受空军警戒雷达干扰的实例,介绍了一种高功率脉冲对雷达发射机干扰的分析过程,并提出解决方法。     

Feedback of Active Galactic Nuclei in Seyfert 2 Galaxies

It is well accepted that feedback from active galactic nuclei (AGNs) plays an important role in the coevolution of the supermassive black hole (SMBH) and its host galaxy,but the concrete mechanism of feedback remains unclear.A considerable body of evidence suggests that AGN feedback suppresses star formation in the host galaxy.We assemble a sample of Seyfert 2 galaxies with recent observational data of compact nuclear starbursts and estimate the gas surface density as a function of column density to illuminate the relation between feedback and AGN properties.Although there are some uncertainties,our data still imply the deviation from the star formation law (Kennicutt-Schmidt law).Further,they indicate that:(1) Feedback correlates with the Eddington ratio,rather than with the mass of SMBH,as a result of decreasing star formation efficiency.(2) The SMBH and the torus are probably undergoing coevolution.Conclusions presented here can be refined through future high resolution CO or HCN observations.     

Precise Synchrotron Radiation Spectrum of Fast-cooling Electrons and the Prompt GRB Emission

It is generally believed that the synchrotron radiation of electrons from the internal shock is the main radiation mechanism of the prompt GRB (gamma-ray burst) emission. However, what this model predicts can not explain observations well. In this paper, we confirm that electrons are quickly cooled due to radiation losses and also point out that the synchrotron radiation spectrum presented in previous papers is a relatively rough estimation. We get the precise synchrotron radiation spectrum of fast-cooling electrons by carrying out a numerical calculation, and thereby reasonably explain the observed distribution of low-energy spectral index (α) of long GRBs based on a unified model. In addition, we fit the correlation between α and the peak energy of the νFν spectrum (E_p).     

Star forming activities in W75N and DR21 – Are the two regions in collision?

We have observed the massive star formation region W75N in ¹²CO J = 3 ? 2 with KOSMA. The profile of ¹²CO J = 3 ? 2 indicated that besides the 9 km s^?1 component, there is another component of ?3 km s^?1, which is associated with another star formation region, DR21N, located to the north of DR21. We derived the physical and dynamical parameters of the core and high velocity gas associated with the two components separately. Star forming activities were investigated, including outflows and infall analysis. The two regions overlap in space and are not connected in velocity. We found that the cloud–cloud collision scenario may not apply for the DR21/W75N case.     

Geochemical anomaly structure of South Mining District of Fenghuangshan Copper Mine

To study the geochemical anomaly structure of multi-element associations in the South Mining District of the Fenghuangshan Copper Mine,samples were collected and analyzed for their trace element contents.Multi-element anomaly associations were divided according to the correlations between Cu and each of the other elements,and the distribution characteristics of multi-element anomaly associations were also described.Among them,the anomaly distribution of metallogenic element Cu indicates the environment of mineralization.This study provided the basis for research on the metallogenic prediction and geochemistry of the Fenghuangshan Copper Mine.