高校网络文化建设探析

高校网络文化是网络文化的重要组成部分,加强高校网络文化建设的一个重要方面,就是要把传统文化产业推向数字化发展,建立网络文化平台,通过网络提供文化服务。本文以首批中国大学视频公开课的开通为例,进一步分析和阐述了社会主义文化大发展大繁荣背景下的高校网络文化建设。     

A New‐Keynesian DSGE model for forecasting the South African economy

This paper develops a New‐Keynesian Dynamic Stochastic General Equilibrium (NKDSGE) model for forecasting the growth rate of output, inflation, and the nominal short‐term interest rate (91 days Treasury Bill rate) for the South African economy. The model is estimated via maximum likelihood technique for quarterly data over the period of 1970:1–2000:4. Based on a recursive estimation using the Kalman filter algorithm, out‐of‐sample forecasts from the NKDSGE model are compared with forecasts generated from the classical and Bayesian variants of vector autoregression (VAR) models for the period 2001:1–2006:4. The results indicate that in terms of out‐of‐sample forecasting, the NKDSGE model outperforms both the classical and Bayesian VARs for inflation, but not for output growth and nominal short‐term interest rate. However, differences in RMSEs are not significant across the models. Copyright © 2008 John Wiley & Sons, Ltd.     

辛伐他汀对小鼠结肠癌细胞CT26凋亡的诱导作用及机理研究

考察了辛伐他汀对小鼠结肠癌细胞CT26生长率的影响,并探究其对CT26细胞凋亡的诱导作用及机理。以四甲基偶氮唑盐微量酶反应比色法测定辛伐他汀对CT26细胞生长的抑制情况;以蛋白质免疫印迹法测定细胞凋亡和增殖的标志蛋白PARP、Cleaved-PARP、P21和磷酸化的P53的蛋白表达水平;以AMPK的抑制剂Compound C来阻断AMPK信号途径后,观察辛伐他汀对CT26细胞中Cleaved-PARP表达的影响;以Compound C处理CT26细胞后,以RT-PCR和蛋白质免疫印迹法测定辛伐他汀在CT26细胞中诱导KLF2和KLF4的情况.辛伐他汀可以明显抑制CT26细胞生长,可以诱导CT26细胞中的凋亡相关的Cleaved-PARP蛋白上升,并且其作用机理可能和KLF4的上升有关.     

Hyperspherical study of Ne2Kr and Ne2Xe systems

We have calculated the ground state energies and rotational constants for the Ne₂ Kr and Ne₂ Xe systems, as well as their corresponding isotopes using the hyperspherical method. We used B-splines as basis function to expand channel functions and make the knot distribution of B-splines characterize the behavior of the channel function precisely. As a result, the extremely slow convergence of quantum mechanic calculation for these van der Waals trimers containing heavy element is improved greatly. The convergent rotational constants and the isotope shifts are obtained and compared with other theoretical and experimental values. Our results using newly proposed Tang-Toennies （TT） pair-wise potentials are consistent with that of Ernesti and Hutson’s calculation using HFD-B potentials, and give an improved agreement with experimental data.     

Changes in plant community diversity and aboveground biomass along with altitude within an alpine meadow on the Three-River source region

The grassland is an important component of terrestrial ecosystems and plays a significant role in biodiversity and ecosystem functions.In the present study,the changes of plant species diversity and aboveground biomass productivity were examined along with the altitude in natural alpine grassland in the source region of three rivers on the Qinghai-Tibetan Plateau.Eleven experimental locations were selected with altitudes ranging from 3862 to 4450 m above sea level(a.s.l.).The results indicated that Kobresia pygmaea meadow,Kobresia humilis meadow and Salix cupularis shrub meadow had higher indices of diversity and aboveground biomass.The distribution of species diversity,richness and aboveground biomass showed similarly unimodal patterns across the altitude gradient with the highest indices appeared at mid-altitudes locations.The changing trend of species diversity,richness and evenness also showed significant unimodal patterns with total aboveground biomass,and the highest species diversity occurred at intermediate level of productivities.This research would provide a valuable reference for the protection of grassland biodiversity and maintaining of the grazing ecosystem function in the source region of the Three Rivers.     

高速公路入口匝道汇合控制下的道路通行能力

研究了高速公路入口匝道实行汇合控制下的通行能力，在以往的研究中通常把可接受间隙作为一个固定参数进行计算，在本文中，则把可接受间隙作为一个概率分布来研究，同时本研究根据主线车流车头时距分布，给出了各级服务水平下道路通行能力的计算公式，并给出了仿真结果。     

Paleomagnetic data from Early Cretaceous volcanic rocks of West Liaoning: Evidence for intracontinental rotation

Detailed rock magnetic studies of 55 lavas from Yixian and Fuxin area, West Liaoning, show the primary carriers of remanence to be pseudo-single domain titanomagnetite. K/Ar dating indicates that the volcanic sequence spans 93 to 133 Ma. Stepwise thermal demagnetization successfully isolated well-defined characteristic magnetization (ChRM) in all lavas thermal-treated above 250℃. The mean paleodirections are D/I = 5.9°/58.8° (α95 = 2.9°) and D/I =179.2°/-59.9° (α95 = 5.2°) for 27 normally magnetized flows and 28 reversibly magnetized flows, respectively. It indicates that since the Early Cretaceous there is no significant horizontal movement and rotation between the Yixian-Fuxin area and Eurasia. However, Korea Peninsula may have undergone a clockwise rotation of 33.9° relative to the Yixian-Fuxin area during the Cretaceous. On the basis of characteristics of hotspot origins (core-mantle boundary or upper mantle), the clockwise rotation of Korea Peninsula relative to Eurasia is assumed to be mainly caused by an extensional force in the crust of eastern China, which was corresponding to intensive surface volcanic activities in this area.     

A combined study of SHRIMP U-Pb dating, trace element and mineral inclusions on high-pressure metamorphic overgrowth zircon in eclogite from Qinglongshan in the Sulu terrane

Methods recently advanced for discrimination on the genesis of metamorphic zircon, such as analysis of mineral inclusions and trace elements, provide us powerful means to distinguish zircon overgrowth during high-pressure metamorphism. Zircons in ultrahigh-pressure eclogite from Qinglongshan in the Sulu terrane were studied by the SHRIMP U-Pb method in combining with trace element and mineral inclusion analyses. No inherited core was identified in the analyzed zircons by means of cathodoluminescence images. The occurrence of high-pressure metamorphic mineral inclusions in zircon, such as garnet, omphacite, rutile, and the flat HREE pattern in zircon indicate that the zircon formed at high-pressure metamorphic conditions. Therefore, a weighted average U-Pb age of 227.4±3.5 Ma obtained from such a kind of zircon is interpreted to represent the timing of peak nietamorphism for the Qinglongshan eclogite.