An Efficient Method for Real Gas Pseudopressure Calculation

The real gas pseudopressure and the corresponding pressure are among the most important parameters in gas reservoir engineering. The most commonly used method for the calculation of pseudopressure is numerical integration. In 1987 Klins and Biterge proposed a semianalytical method for pseudopressure computation. In this paper, the semianalytical method is modified. The modified method seems to be faster and more accurate, and has a wider range of applicability than the original one.     

Measuring the influence of materials composition on nano scale roughness for wood plastic composites by AFM

Composition of mango wood Polypropylene composites (WPCs) are prepared through melt compounding with the help of micro conical twin screw co-rotating extruder then injection molding of WPCs pellets. Polymer matrix composites are formulated for five compositions with a different weight ratio of wood, virgin polypropylene, recycled polypropylene and coupling agent. Average roughness (Ra), mean peak-to-valley height (Rz) and maximum roughness (Rmax) used to evaluate surface characteristics of samples by AFM. Also measures the 3D surface and surface roughness profile to examine the same. Result from this work clearly shows that recycled Polypropylene based composites with and without coupling agent have a smooth surface in comparison with virgin Polypropylene based composites for same operating variable conditions. The surface smoothness of WPCs improved with decreasing of wood flour content for all samples. By addition of coupling agent surface smoothness of the WPCs increases and the value of Ra decrease from 2.17 to 1.04 nm for recycle polypropylene wood based composite. Surface of composites is also examined with the help of FESEM images. FESEM feature proved that MAPP coupled is shown good bonding strength and smoothness in comparison to none coupled composite for the same class.     

多智能体路径规划研究进展

多智能体路径规划是一类寻找多个智能体从起始位置到目标位置且无冲突的最优路径集合的问题,针对该问题的研究在物流、军事和安防等领域有着大量的应用场景.对国内外关于多智能体路径规划问题的研究进展进行系统整理和分类,按照结果最优性的不同,多智能体路径规划算法被分为最优算法和近似算法2类.最优的多智能体路径规划算法主要分为基于A*搜索、基于代价增长树、基于冲突搜索和基于规约的4种算法.近似的多智能体路径规划算法主要分为无边界次优的算法和有边界次优的算法2类.基于上述分类,分析各种算法的特点,介绍近年来具有代表性的研究成果,并对多智能体路径规划问题未来的研究方向进行展望.     

The modulation of endothelial cell gene expression by green tea polyphenol-EGCG

Human and animal studies have shown that green tea consumption is associated with a reduced risk of some cancers. This has been attributed to its polyphenol components, in particular (-)-epigallocatechin gallate (EGCG). In addition to be a cancer chemopreventive agent, EGCG inhibits angiogenesis, thus reducing tumor growth and metastasis. We tested EGCG modulation on the gene expression profile of endothelial cells stimulated by VEGF using Affymetrix microarrays. A total of 421 genes were up-regulated and 72 genes were down-regulated at the false discovery rate of 5% by VEGF, EGCG, and EGCG pretreatment followed by VEGF stimulation. The changes in the expression of several pivotal genes were validated by real-time PCR. Furthermore, we have identified two signaling pathways (Wnt and Id) involved in cell proliferation were inhibited by EGCG treatment, suggesting the negative regulation of EGCG on cell proliferation. Our results also indicate that the antiangiogenesis effect of EGCG is partially mediated through its broad inhibition on endothelial cell proliferation. Our data further support earlier observations that the anticancer effect of EGCG is mediated through changes in the expression of genes that are associated with cell proliferation.