Butters Varying in <Emphasis Type="Italic">trans</Emphasis> 18:1 and <Emphasis Type="Italic">cis</Emphasis>-9,<Emphasis Type="Italic">trans-</Emphasis>11 Conjugated Linoleic Acid Modify Plasma Lipoproteins in the Hypercholesterolemic Rabbit

The experiment was designed to study the effects of butters differing in conjugated linoleic acid (CLA) and trans 18:1 contents on lipoproteins associated with the risk of atherogenesis. New Zealand White male rabbits (9.6 weeks; 2.1 kg) were assigned for 6 or 12 weeks to three diets (n = 6 per diet) made of conventional pellets with 0.2% cholesterol and with 12% fat provided from a butter poor in trans-10 and trans-11 18:1 and in CLA (standard group), or rich in trans-10 18:1 (trans-10 18:1 group) or rich in trans-11 18:1 and in cis-9,trans-11 CLA (trans-11 18:1/CLA group). Blood samples were collected at the end of dietary treatments. Lipoproteins were separated by gradient-density ultracentrifugation. Lipid classes were determined enzymatically and apolipoproteins A-I and B by radial immunodiffusion. Mainly in the 12-week rabbits, higher plasma triglycerides and apolipoprotein B levels shown in the standard and trans-10 18:1 groups compared with those in the trans-11 18:1/CLA group are associated with higher plasma levels of very low density lipoproteins (VLDL) and low density lipoproteins (LDL) also shown in these two groups. In the 12-week rabbits, a shift towards denser LDL, considered as more atherogenic, was shown only in the trans-10 18:1 group. In these animals, the VLDL + LDL to HDL ratio was 1.7-2.3 times higher in the trans-10 18:1 group than in the other groups (P = 0.076). These results suggest a rather neutral effect of trans-11 18:1/CLA butter towards the risk of atherogenesis, whereas trans-10 18:1 butter would tend to be detrimental.     

Incorporation and metabolism of trans 20∶5 in endothelial cells. Effect on prostacyclin synthesis

To study the ability of long-chain trans fatty acids (FA) to be incorporated and metabolized into endothelial cells, bovine aortic endothelial cells were incubated with medium enriched eicosapentaenoic acid (EPA) bound to albumin (M2) or one of its geometrical isomers: 20∶5 5c,8c,11t,14c,17c(M3), 20∶5 5c,8c,11c,14c,17t(M4), or 20∶5 5c,8c,11t,14c,17t(M5). After 48 h of incubation, supernatant and cells were harvested and their lipids were analyzed, including prostacyclin synthesis. EPA and 22∶5n−3 of endothelial cells incubated with M2 were, respectively, three and two times higher than in control cells (incubated in M1, without any fatty acid added), whereas 22∶6n−3 increased only in the supernatant, suggesting its release after biosynthesis. However, 18∶2n−6 and 22∶4n−6 decreased (about 30%). Trans 20∶5 isomers represented 4.7, 3.9, and 5.2% of total phospholipid FA in endothelial cells incubated with M3, M4, and M5, respectively. They were elongated into trans 22∶5 and trans 24∶5, as revealed by gas chromatography-mass spectrometry and gas chromatography-Fourier transform infrared analysis. In cells incubated with M2, M3, M4, and M5, prostacyclin synthesis was inhibited by 49.0, 62.5, 60.5, and 72.0%, respectively. This effect may be due to less available arachidonic acid in the cells and to a competition between EPA isomers and AA at the level of cyclooxygenase pathway, as it was demonstrated that 20∶5 Δ17t was metabolized by this enzyme.     

基于GIS的南水北调中线水源区生态环境监测体系平台构建

南水北调中线工程水源区生态环境问题非常突出,依据GIS理论,建立一体化的信息监测平台,有利于水源区生态环境保护。在研究GIS在水源区生态环境监测中的应用基础上,对水源区生态环境监测体系的构建进行了研究,包括监测思路对策研究、监测指标体系构建研究、监测体系平台结构设计研究、监测体系平台日常应用研究等,重点对监测体系平台进行了详细的阐述。系统按照应用逻辑自上而下分为应用层、中间层、数据层以及远程监测层;监测体系平台采用了B/S和C/S结构相融合的模式构建,平台功能结构设计了八大数据库和六大应用子系统。     

隔板精馏降苯工艺优化模拟

采用精馏分离降苯技术,以不同含苯质量分数的模拟汽油为研究对象,根据Aspen Plus流程模拟软件中的Petlyuk模块建立隔板精馏模型,利用灵敏度分析对进出物料位置进行优化;此外,在不同回流比条件下,采用序贯二次规划算法对塔顶采出率和侧线采出率双变量进行优化,并与RedFrac常规精馏模型进行了对比分析。结果表明:采用隔板精馏塔,随着回流比的增加,汽油的收率和产值逐渐增加;当含苯质量分数为1%,3%,5%时,最高汽油收率依次为99.53%,96.35%,93.75%。隔板精馏工艺适用于含苯质量分数较低和较高的汽油,而常规精馏工艺更适用于含苯质量分数较低的汽油。     

南水北调西线工程引水区气候变化趋势分析

以南水北调西线工程引水区及邻近地区共13个气象站近60年的降雨、温度、日照时数、平均风速、平均湿度、平均水汽压资料为基础,分别运用Mann-Kendal法、Hurst系数法和小波方法对气象系列进行趋势、持续性和周期性分析。结果表明:各气象站温度年序列均呈显著上升趋势,而四季中的冬季上升尤为明显;降雨年序列92%的站点呈不明显上升趋势,但在春季上升显著;日照年序列64%的站点呈下降趋势。在空间分布上,气候因子趋势显著的站点多集中在河源段。各气象因子的Hurst系数均大于0.5,说明系列正持续性效应明显,未来变化趋势与过去基本一致。此外,各气象因子序列具有较明显的6¹8年震荡周期。     

高分辨率层序地层学在储集层精细描述中的应用

储集层精细描述是老区挖潜、提高采收率的基础,也是已开发油田稳产的关键。由于缺乏资料和地质解释本身的多解性,储集层精细描述中单砂体连通性及规模评价往往存在不确定性。针对这一问题,应用高分辨率层序地层学分析方法,通过综合资料的分析对比,建立等时地层格架及砂体叠置模式,有效指导储集层描述和单砂体精细解剖。以吉林油田黑59区块注气储集层为例,进行储集层精细描述和单砂体精细解剖,明确了储集层纵、横向分布规律,刻画了单一成因砂体发育期次、规模等特征,实现了单砂体分布在三维空间的可视化。     

蜂群算法在带时间窗的车辆路径问题中的应用*

根据带时间窗车辆路径问题的实际情况,通过考察车辆数和总行程两个目标函数,给出了该问题的一种新的算法——蜂群算法。通过计算若干benchmark问题,并将结果与其他算法相比较分析,验证了算法的有效性。目前关于蜂群算法的文献较少,故不仅是拓宽蜂群算法应用范围的有效尝试,同时也给带时间窗车辆路径问题提供了一种新的解决方法。     

基于GA-Transmodeler的动态OD矩阵估计方法*

采用系统仿真与遗传优化算法相结合的方法完成离线状态下多时段OD矩阵的估计。系统仿真旨在对多时段的动态OD矩阵实现连续动态交通分配,以得到在各个时段的OD流量对观测路段的分配比例矩阵,遗传算法则通过种群内个体的交叉、变异等遗传算子求解最优条件下的OD矩阵。仿真结果表明,这种仿真优化结合的方法能够充分体现动态交通流的延续性,且遗传算法具有较强的全局收敛性。     

真实感人脸语音同步动画系统*

提出了一个人脸动画与语音同步的系统,重点解决协同发音、表现人脸细微表情特征的问题。输入带有情绪标志的文本,就能够产生对应表情的、与语音同步的人脸动画;本系统能够生成各种不同性别、年龄、表情特征的高度真实感3D人脸模型,人脸细微表情特征(如额头皱纹)可以随人脸表情的变化而动态改变。基于语言学理论,本系统提出了解决协同发音问题的一套规则。