基于支持向量机的不锈钢冷轧薄板力学性能的预测模型

介绍了支持向量机(SVM)技术中的支持向量机回归模型原理,建立了不锈钢冷轧薄板力学性能预测模型.结果表明,随着训练样本的增加,模型的预测精度也得到提高.证明应用支持向量机构建不锈钢冷轧薄板力学性能预测的数学模型,能较好地解决小样本和模型预测精度间的矛盾,具有较强的泛化能力.     

非酶棕色化反应在烟草增香中的应用研究

文章研究了以天然大豆粉水解液提供氨基酸与葡萄糖或其它羰基化物之间的非酶棕色化反应在烟草增香中的作用，并与己酸和葡萄糖反应的棕色化产物进行对比，认为大豆粉水解液的棕色化产物对烟草增香效果更佳，对烟草薄片的改进作用更为显著。     

Inter-hemispheric comparison of climate change in the last millennium based on the ECHO-G simulation

The commonality and difference in the variations of temperature and precipitation between the Northern Hemisphere （NH） and Southern Hemispheres （SH） in the last millennium are investigated by analysis of the millennium simulation with the ECHO-G coupled climate model. The NH mean temperature variations are generally consistent with those of the SH counterpart on the interannual, decadal and centennial time scales. But, the transition times between the medieval warm period （MWP）, the little ice age （LIA）, and the present-day warm period （PWP） in the NH leads that in the SH; and the anomaly amplitude in the NH is significantly larger than the SH counterpart. For the precipitation variations, the NH mean precipitation varies in-phase with the SH mean precipitation on decadal and centennial scales （mainly in the mid-high latitudes） but out-of-phase on the interannual scale （mainly in the low latitudes）. During the MWP the warming has comparable amplitude in the NH and SH; however, during the PWP the NH warming is considerably stronger than the SH warming. Further, the present-day temperature rises in the NH high latitudes but decreases in the SH high latitudes, which is very different from the warming pattern during the MWP. Since during the MWP the greenhouse gases （GHG） concentration stayed at a low level, we infer that the present-day opposite temperature tendency in the high latitudes between the two hemispheres may be related to the increase of the GHG concentration.     

黄金口“T”型褶皱构造的力学分析

对川东北黄金口构造特征进行了较详细的描述,并在此基础上对其早晚两期应力场作了讨论,用赤平投影方法和计算机解析计算了最大主应力、最小主应力、最大剪应力和主偏应力方向和大小。对岩石有限应变作了Ｆｒｙ法测量和分析,并用弹性力学有关曲薄板在轴向压缩下屈曲原理对黄金口构造形成力学机理进行了初步探讨。     

异步轧制AZ31镁合金板材组织

对不同总变形量、道次压下量、轧制温度以及轧制路径等工艺条件下所制备的AZ31镁合金板材的组织进行研究。研究结果表明：异步轧制有利于板材的晶粒细化,其晶粒粒度约为8．9μm,明显小于常规轧制板材的13．2μm;当总变形量由40％增大到80％时,晶粒粒度从40μm左右减小到30μm左右,出现了较多的孪晶;当道次压下量由5％增加到20％时,晶粒粒度从40μm左右减小到10～20μm,孪晶数量也随之减少;当温度由350℃升高到400℃时,晶粒粒度由20μm左右下降到10μm,且大部分晶粒为等轴晶;轧制路径的改变,使板材中的显微组织和孪晶数量产生改变,C路径中的晶粒细小,粒度约为10μm,D路径中的孪晶数量最少。     

整体无阀机构太阳能冰箱的应用研究

在太阳能固体吸附循环制冷的基础上，采用无阀机构连接优化设计后的吸附床、冷凝器、蒸发器，构建成新型无阀机构的太阳能冰箱．将该太阳能冰箱分别在实验室内及实验室外进行静态实验及动态实验，得出了系统在一定辐射能量后的对外性能特性．所开展的研究工作为实用化的太阳能冰箱奠定了基础．     

1Cr18Ni9Ti不锈钢薄板等离子电弧加热弯曲成形的温度场

为获得等离子电弧加热工艺参数和薄板几何尺寸对薄板温度场分布的影响规律,应用有限元方法对1Cr18Ni9Ti不锈钢薄板等离子电弧加热弯曲成形的三维瞬态温度场进行了数值模拟,分析了等离子电弧功率、扫描速度、薄板厚度以及冷却条件等对等离子电弧成形温度场的影响特性.结果表明:1Cr18Ni9Ti不锈钢薄板的弯曲角度随着等离子电弧功率的增加而增加,最佳扫描速度下薄板厚度方向温度梯度达到最大.改变温度梯度可以达到控制变形的目的.     

基于史料记载的1470～1949年广东沿海地区台风活动历史重建与分析

根据史料文献记载,并结合现代台风活动特征,对历史时期（公元14701949年）广东沿海地区的台风活动进行了重建,采用相关性分析和交叉小波分析方法探讨了历史时期的台风活动、北半球平均气温以及太平洋年代际震荡（Pacific Decadal Oscillation, PDO）相互之间的关系. 研究结果显示: (1)重建的历史时期台风活动年均频次与现代台风活动统计结果比较接近,二者在登陆区域上的分布比例也基本一致; (2)近500年来北半球平均气温与影响广东沿海地区的台风活动频次之间存在较为显著的正相关性,特别是在PDO暖位相时期二者之间的正相关性显著提高,这在一定程度上意味着在当前全球变暖背景下影响广东沿海地区的台风活动频次有可能增多.     

基于BP神经网络的输电线路覆冰增长模型研究

分析了现有输电线路覆冰增长模型在预测中的不足以及神经网络对非线性映射变量表达的优越性,提出了一种基于Levenberg-Marquardt学习算法的BP神经网络的覆冰增长预测模型。通过实验获取的覆冰增长数据样本训练BP网络,利用收敛的网络进行输电线路覆冰增长的预测,仿真实验误差1mm以下的有7组数据,远高于对比模型makkonoe模型的3组,验证了模型有效性,对输电线路的覆冰研究和预防有重要意义。     

Recent temperature increase recorded in an ice core in the source region of Yangtze River

Interests on climate change in the source region of Yangtze River have been raised since it is a region with the greatest warming over the Tibetan Plateau (TP). A 70-year history of precipitation δ~(18)O has been recovered using an ice core record retrieved in a plat portion of the firn area in the Guoqu Glacier (33°34′37.8″N, 91°10′35.3″E, 5720 m a.s.l.), Mt. Geladaindong (the source region of Yangtze River), in November, 2005. By using a significant positive relationship between ice core δ~(18)O record and summer air temperature (July to September) from the nearby meteorological stations, a history of summer air temperature has been reconstructed for the last 70 years. Summer temperature was relatively low in 1940s and high in 1950s to the middle of 1960s. The lowest temperature occurred in the middle of 1970s. Temperature was low in 1980s and dramatically increased since 1990s, keeping the trend to the begin-ning of the 21st century. The warming rate recorded in the ice core with 0.5℃/10 a since 1970s is much higher that that in the central TP and the Northern Hemisphere (NH), and it becomes 1.1℃/10 a since 1990s which is also higher than these from the central TP and the NH, reflecting an accelerated warm-ing and a more sensitive response to global warming in the high elevation region.