基于OPNET的MVB总线仿真研究     

黄东  魏志强 《教育技术导刊》2011,10(1):52-54

列车网络控制技术是高速列车发展的一项关键技术.为了评估多功能车辆总线(Multiple Vehicle Bus,MVB)车辆级网络通信系统的性能,优化网络设计,采用Opnet Modeler搭建车辆级通信网络模型,包括车辆的网络拓扑结构模型、链路模型、节点模型和进程模型.利用所搭建的模型,对车辆级通信网络的时延性、吞吐...  相似文献   

金融危机背景下的高等教育危机     

董泽芳  张茂林 《高教发展与评估》2011,27(3)

高等教育危机埋下了引发金融危机的祸根,培养了造成金融危机的人才;金融危机进一步强化了高等教育经费危机,加剧了高等教育就业危机,加深了高等教育质量危机。在金融危机背景下化解高等教育危机,政府要调整高等教育战略,加大高等教育投入;高校要以提高质量为中心,加强师资队伍建设。  相似文献   

茨威格与阿来作品中的民族意识比较——从后殖民批评理论的角度分析二者的“流放”与“寻根”     

英思悦 《鸡西大学学报》2011,11(9):120-122

茨威格和阿来分别是犹太民族和藏民族的杰出代表,他们自身以及其作品自然的渗透出强烈的民族意识,由于作家的成长经历和时代背景,使其作品中表现出＂流放＂和＂寻根＂的后殖民批评理论的特点,因此无论是在地域、种族、文化、宗教等方面的流放,民族意识觉醒后的寻根,还是共同存在的表现各异的人道主义关怀,均是真正把握两者民族意识之间的共性和异性的咽喉。  相似文献   

试析政党在加拿大联邦制演变中的角色表现     

贾瑛 《鸡西大学学报》2011,11(2):143-144

纵观加拿大历史,不难发现其联邦制是由集权性联邦向分权性联邦演变的,到了20世纪下半叶,甚至有人认为加拿大省所拥有的权力和地位,可能会令联合国许多主权国家感到羡慕,可见其省享有主权之大。而在省权扩大的历程中政党所扮演的角色不容忽视。  相似文献   

比较思想政治教育研究者学养提升的四个维度     

王颖 《思想政治教育研究》2011,27(1):56-57,90

提高比较思想政治教育研究者的学养和能力,迅速完善专业学术共同体是目前最紧迫的工作。比较思想政治教育研究者要了解思想政治教育学学科发展的总体趋势;有一个相对熟悉的主攻国度;锁定自己的主攻领域或专题;有一个基本的立足点和主攻视角。  相似文献   

大数据对档案文献编纂工作的启示     

白颖  刘山山 《兰台世界》2019,(8):45-48

大数据的兴起和发展,给档案实践带来了新思路和新方式。档案文献编纂因其固定的工作环节在大数据的适应上有所滞后,通过辨析大数据和档案文献编纂工作的关系,以及对大数据下档案文献编纂工作现状的探析,探讨大数据对档案文献编纂工作的启示,借助大数据实现档案文献编纂工作的过程优化,以及编纂成果多样化的目的。  相似文献   

Ds-echinoside A, a new triterpene glycoside derived from sea cucumber, exhibits antimetastatic activity via the inhibition of NF-κB-dependent MMP-9 and VEGF expressions     

Zhao Q  Liu ZD  Xue Y  Wang JF  Li H  Tang QJ  Wang YM  Dong P  Xue CH 《Journal of Zhejiang University. Science. B》2011,12(7):534-544

Ds-echinoside A (DSEA), a non-sulfated triterpene glycoside, was isolated from the sea cucumber Pearsonothuria graeffei. In vitro and in vivo investigations were conducted on the effects of DSEA on tumor cell adhesion, migration, invasion, and angiogenesis. In this study, we found that DSEA inhibited the proliferation of human hepatocellular liver carcinoma cells Hep G2, with a half-maximal inhibitory concentration (IC₅₀) of 2.65 μmol/L, and suppressed Hep G2 cell adhesion, migration, and invasion in a dose-dependent manner. DSEA also reduced tube formation of human endothelial cells ECV-304 on matrigel in vitro and attenuated neovascularization in the chick embryo chorioallantoic membrane (CAM) assay in vivo. Immunocytochemical analysis revealed that DSEA significantly decreased the expression of matrix metalloproteinase-9 (MMP-9), which plays an important role in the degradation of basement membrane in tumor metastasis and angiogenesis. DSEA also increased the protein expression level of tissue inhibitor of metalloproteinase-1 (TIMP-1), an important regulator of MMP-9 activation. From the results of Western blotting, the expressions of nuclear factor-kappa B (NF-κB) and vascular endothelial growth factor (VEGF) were found to be remarkably reduced by DSEA. These findings suggest that DSEA exhibits a significant antimetastatic activity through the specific inhibition of NF-κB-dependent MMP-9 and VEGF expressions.  相似文献   

A case study of imported pulmonary coccidioidomycosis     

Wang ZY  Wen SL  Ying KJ 《Journal of Zhejiang University. Science. B》2011,12(4):298-302

Coccidioidomycosis is an endemic disease of the Western hemisphere. The cases in non-endemic areas are mostly imported. Determining a history of exposure is critical for performing the diagnosis of coccidioidomycosis, especially for cases occurring in a non-endemic area. In this study, a 71-year-old Chinese male presented to our hospital with chronic cough and malaise, and was found to have a mass in the middle lobe of right lung. He had been visiting Arizona, USA for four months before admission. Pulmonary coccidioidomycosis was confirmed by the results of histopathological examination after lobectomy. Typical microscopic features of Coccidioides are definitely diagnostic, but need be differentiated from other budding yeast infection or carcinoma histopathologically.  相似文献   

Characterization of (68)Zn uptake, translocation, and accumulation into developing grains and young leaves of high Zn-density rice genotype     

Wu CY  Feng Y  Shohag MJ  Lu LL  Wei YY  Gao C  Yang XE 《Journal of Zhejiang University. Science. B》2011,12(5):408-418

Zinc (Zn) is an essential micronutrient for humans, but Zn deficiency has become serious as equally as iron (Fe) and vitamin A deficiencies nowadays. Selection and breeding of high Zn-density crops is a suitable, cost-effective, and sustainable way to improve human health. However, the mechanism of high Zn density in rice grain is not fully understood, especially how Zn transports from soil to grains. Hydroponics experiments were carried out to compare Zn uptake and distribution in two different Zn-density rice genotypes using stable isotope technique. At seedling stage, IR68144 showed higher ⁶⁸Zn uptake and transport rate to the shoot for the short-term, but no significant difference was observed in both genotypes for the long-term. Zn in xylem sap of IR68144 was consistently higher, and IR68144 exhibited higher Zn absorption ratio than IR64 at sufficient (2.0 μmol/L) or surplus (8.0 μmol/L) Zn supply level. IR64 and IR68144 showed similar patterns of ⁶⁸Zn accumulation in new leaves at seedling stage and in developing grains at ripening stage, whereas ⁶⁸Zn in new leaves and grains of IR68144 was consistently higher. These results suggested that a rapid root-to-shoot translocation and enhanced xylem loading capacity may be the crucial processes for high Zn density in rice grains.  相似文献   

TIN地形曲面任意点法向量的高精度解算模型     

赵静  王栋  王春  李鹏 《滁州学院学报》2011,13(2):15-17

曲面法向量是基于TIN完成数字地形解析分析的重要参考基础。本文首先分析了TIN中的三角形形状与地形曲面姿态的关系问题,然后构建了以地形曲面形态的"相近相似"特征为基点的V-Rub法向量解算模型。实验结果显示,V-Rub模型解算法向量的精度高,速度快,具有很好的实用价值。  相似文献