An Optimization Method For Estimating Phase Compositions And Amounts In Two—Phase Nickel Base Superalloys

根据已知镍基合金成分和γ′相成分，运用分层宽容多目标优化法，分别计算了γ相成分及γ′相含量．优化测算过程的实现是通过建立使杠杆定律等式两端数值差最小和两相共格错配度最小的目标函数，并通过设置γ′相含量和基体相成分取值范围的约束条件而实现的．验证了该方法的可行性和准确性．     

2002年中国汽车工业动态

本简要描述了中国汽车工业的发展过程及发展前景、产品结构变化、产销量以及中国汽车生产企业状况等。     

伪随机流场法在堤坝渗漏探测中的应用与研究

伪随机流场法具有快捷、直接、精确有效等优点,逐步成为堤坝渗漏探测的主流方法。利用该方法,在漏水区域、库区无穷远段进行高压供电,库区内网格状布置测点,可查找渗漏入水点。通过对各异常区域的区域面积、异常区域内各测点的异常平均值以及对于严重渗漏的临界值进行计算,可判断水库渗漏通道和各渗漏点的渗漏量比例。此外,由于该方法快速便捷的特点,可以运用该方法进行实时监测。应用于某混凝土面板堆石坝的探测结果表明,利用堤坝周边已经存在的监测孔或在灌浆帷幕下游进行钻孔,进行伪随机电位差或者电流测试,可在无损条件下判断渗漏来源和通道发育方向,检测防渗处理效果。该方法可为堤坝渗漏监测预警、拟定防渗处理方案提供依据。     

鱼类下行过坝的导鱼栅系统设计及试验研究

以龙开口水利枢纽为例,提出一种辅助鱼类下行过坝的导鱼栅系统方案。该方案首先结合大坝泄流建筑物的特点确定导鱼栅系统的布置位置,然后以鳙鱼为试验对象,用控制变量法并选择四种导鱼栅叶片角（15°、30°、45°、90°）和三种导鱼栅布置角（15°、30°、45°）在室内开展模型试验,以确定最优运行工况。研究结果表明,导鱼栅系统布置在该枢纽的灌溉引水口最佳。试验中,当布置角控制为30°时,四种叶片角下的鱼类通过率分别为53%、95%、59%和72%;当叶片角控制为30°时,三种布置角下的鱼类通过率分别为53%、95%和41%。因此,在导鱼栅叶片角和布置角同为30°时,导鱼栅系统辅助鱼类下行的效率最高,通过率为95%。研究成果可为我国类似导鱼栅系统设计提供参考。     

Comparison of the Effect of a Hydrocarbon Oil and a Terpene Tackifier on the Autohesion of Styrene-Butadiene Rubber

Blends of uncrosslinked styrene-butadiene rubber (SBR) with a terpene tackifier resin or a naphthenic oil have been characterized, and their autohesion and cohesion determined using a T-peel geometry. SBR/oil blends are homogeneous at all proportions, while SBR/resin blends, based on DSC and DMA analysis, undergo bulk phase separation at about 50% resin. However, migration of tackifier to the surface region is proposed at much lower resin contents. Compositions diluted with oil have autohesion similar to the neat SBR. This is attributed to compensating effects; although oil hastens self-bond formation by increasing chain mobility, this is nearly equally balanced by more facile chain separation during bond rupture. In short, oil-diluted compositions are soft and weak. On the other hand, SBR compositions containing small amounts of resin have high autohesion. Resin-diluted specimens deform easily at low strain, just as those containing oil, but intertwined chains of the former have greater resistance to separation, due at least in part to higher glass transition temperatures. It is proposed that autohesion is further enhanced by migration of tackifier to the surface. This causes SBR/resin compositions to be both soft and strong-a necessary condition for high autohesion.     

Performance of a Vertical‐Slot Fish Pass for the Sea Lamprey Petromyzon marinus L. and Habitat Recolonization

In 2011, a vertical‐slot fish pass was built at the Coimbra Açude‐Ponte dam (Mondego River, Portugal), approximately 45 km upstream from the river mouth. The performance of this infrastructure for sea lamprey passage was evaluated between 2011 and 2015 using several complementary methodologies, namely radio telemetry [conventional and electromyogram (EMG)], passive integrated transponder (PIT) telemetry and electrofishing surveys. During the study period, the electrofishing revealed a 29‐fold increase in the abundance of larval sea lamprey upstream of the fish pass. Of the 20 radio‐tagged individuals released downstream from the dam, 33% managed to find and successfully surpass the obstacle in less than 2 weeks, reaching the spawning areas located in the upstream stretch of the main river and in one important tributary. Fish pass efficiency was assessed with a PIT antenna installed in the last upstream pool and revealed a 31% efficiency, with differences between and within migratory seasons. Time of day and river flow significantly influenced the attraction efficiency of the fish pass, with lampreys negotiating it mainly during the night period and when discharge was below 50 m³ s^?1. Sea lampreys tagged with EMG transmitters took 3 h to negotiate the fish pass, during which high muscular effort was only registered during passage, or passage attempts, of the vertical slots. The use of complementary methodologies provided a comprehensive passage evaluation for sea lamprey, a species for which there is a considerable paucity of valuable data concerning behavioural, physiological and environmental influences on obstacle negotiation. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.     

Fat-simulating and accelerating solvents for polyolefins and MWD of solvent extracts of polyethylenes

Migration kinetics of straight-chain oligomers and antioxidants from several polyolefins at different temperatures into various solvents have been studied by radioactive tracer techniques. Anhydrous ethanol appears to be a well suited food-oil or liquid-fat simulant for extracting different types of migrants from polyolefins. Pure and mixed triglycerides are also good oil or fat simulants, but the triglycerides offer no simpler analytical procedures than the use of oil or fat themselves. n-Octanol may also be considered as a reasonable oil or fat simulant; however, its action depends somewhat on the choice of migrants. The accelerating action of n-heptane over that of oil or simulants is quantitatively demonstrated. The accelerating effects are greater for migration systems with lower diffusion coefficients. The diffusion coefficients for migration into n-heptane are about 20 times greater than the diffusion coefficients into ethanol or oil for otherwise identical migration systems yielding diffusion coefficients of about 10^?7 cm²s^?1 into oil or ethanol. For systems yielding diffusion coefficients into oil or ethanol of about 10^?12 cm²s^?1, the corresponding diffusion coefficients into n-heptane are about 1000 times greater. The molecular weight distributions (MWDs) of the n-heptane and ethanol extracts of polyolefins have been analysed. n-Heptane can not only accelerate the migration of the individual migrant but also remove oligomer species that are slightly soluble or present at low levels in the oil or simulant extracts.     

提高PVC糊树脂质量小结

叙述了降低PVC糊树脂产品中氯乙烯残留量、稳定糊黏度的措施。通过改进，提高了产品质量。     

Si加入量对Si_3N_4-SiC复合材料性能的影响

固定其他组分配比不变,仅改变配方中Si粉加入量即Si粉从10％增加到60％,经过准静态氮化法反应烧结制得Si3N4——SiC复合材料,并对其进行力学性能、XRD和SEM检测,实验结果显示:随着Si加入量的增加,复合材料的强度逐渐增大,而密度却呈现减小趋势,生成的Si3N4-中β-Si3N4含量增加,形成的网络结构的致密度也相应增大,但β-Si3N4晶粒减小。     

磁盘阵列环境下的取证目标系统重构

封存原始硬盘与业务系统服务的连续性是计算机取证中面临的一对矛盾。在独立硬盘环境中,问题的解决并不困难,但在磁盘阵列(RAID)环境下,目前还缺乏有效的解决办法。为此,为RAID环境下的取证目标系统的重构提出一套解决方案,并设计实现其中关键任务的处理软件。实验表明,该方法可适用于不同RAID等级、不同操作系统下的系统重构,使得用户感受不到重构得到的系统与原系统有任何差异。与数据同步方法相比,该方法可以有效地减少重构的时间开销,且不会破坏原始证据硬盘上的数据。